This is CNBC's live blog tracking Saturday's developments in Russia's attack on Ukraine. See below for the latest updates.

Ukraine said on Saturday that Russian forces blew up a Kharkiv gas pipeline on Saturday. Meanwhile, the U.S. and several allies touted a plan to restrict Russia's financial capabilities.

Earlier in the day Ukrainian President Volodymyr Zelenskyy said Kyiv had managed to repel Russian attacks overnight and that his army remained in control of the capital. Ukraine said Russian missiles hit an apartment building in Kyiv as Russian troops closed in.

Here are links to additional CNBC coverage of the Russian invasion of Ukraine:

• Ukraine fight isn't proceeding as quickly as Russia expected, U.S. Defense official says
• Photos show global outrage at Russia's decision to invade Ukraine
• 'People are literally afraid to sleep': Living under Russian bombs in Ukraine

Separate blasts at oil facilities in Kharkiv and Vasylkiv risk causing environmental catastrophes

Two separate Russian missile attacks on oil and gas facilities in northern Ukraine late Saturday caused massive explosions and fires that could easily become environmental catastrophes, according to Ukrainian officials in the cities impacted by the blasts.

In Kharkiv, Ukraine's second-largest city, Russian troops fired a missile that hit a major gas pipeline late Saturday night, local officials said. The resulting blast was so massive that it prompted the government to specifically caution residents that what they had seen was not a nuclear bomb.

"This is NOT a nuclear strike, although the explosion is visually similar to it," the Kharkiv government Telegram channel warned, according to an NBC translation of the message.

The channel advised residents to close their windows, purify the air if possible and prepare to wear wet masks if they smelled smoke.

Around 250 miles west of Kharkiv, the same advisory was issued to residents in and near the Ukrainian capital of Kyiv after Russian troops blew up a fuel tank in Vasylkiv.

According to the regional governor of the state where Kyiv is located, the missile attack cut off Vasylkiv's gas supply and caused a fire so large that it could be seen 15 miles away in the capital. Fierce fighting between Russian and Ukrainian forces prevented first responders from extinguishing the fire, the governor said in a Telegram post.

"This night, the occupiers are causing man-made disasters," said the local government of Kharkiv.

The attacks on the fuel lines came as invading Russian troops encountered resistance Saturday and early Sunday from the Ukrainian military, which managed to hold all three of the cities Moscow had targeted: Kyiv, Kharkiv and Kherson.

U.S. officials said Saturday they believe Russian President Vladimir Putin was unprepared for the tenacity of Ukraine's military response.

They said Putin was mistakenly convinced that Ukraine's military would collapse within hours of a Russian invasion, and its president Volodomyr Zelenskyy would flee. Neither of these happened.

—Christina Wilkie

Over 240 civilians in Ukraine injured and 64 dead so far in Russian invasion, UN says

More than 240 civilians have been injured, including 64 who were killed, since Russia first invaded Ukraine on Thursday, the United Nations said Saturday.

Hundreds of thousands of people are without electricity or water following damage to civilian infrastructure. Homes, bridges and roads have been destroyed by shelling that cut off communities from markets, the United Nations High Commissioner for Refugees said.

The relief agency said over 160,000 people have been internally displaced, while more than 116,000 have fled into neighboring European countries. Ukraine's government estimates there could be some 5 million refugees in the worst-case scenario.

"UN agencies and humanitarian partners have been forced to suspend operations due to the deteriorating security situation," according to the agency's latest situation report.

—Joanna Tan

Inside a Kyiv residential building hit by a rocket

Photographs reveal the interior of apartments in a Kyiv building after a rocket hit it on Saturday. The Los Angeles Times' Marcus Yam made the pictures.

—Adam Jeffery

One woman killed as residential building in Kharkiv comes under fire

An elderly woman was killed when Russian forces attacked a nine-story residential building in Kharkiv, a northeastern city in Ukraine. Rescue workers evacuated about 20 people from the rubble, NBC reported.

The shelling destroyed structural elements of the building and several floors, and an elderly woman who lived on the fifth floor was killed. Some 60 people were hiding in the basement of the building, but no one was reported to be injured.

— Joanna Tan

Refugees continue to flee Ukraine

Ukrainian refugees have been fleeing the country as Russia continues its assault. Refugees have been pouring into Poland, Slovakia and Hungary.

—Adam Jeffery

Ukraine defenders, logistical problems thwart Russian attacks

Stubborn Ukrainian resistance and logistic difficulties continue to impede Russian troops more than Moscow planners expected, according to U.S. and U.K. officials.

"Russian forces are not making the progress they had planned. They are suffering from logistical challenges and strong Ukrainian resistance," the U.K.'s Ministry of Defence said on its Twitter account.

The British report corroborates information shared with CNBC by a U.S. Department of Defense official on Friday.

The U.S. official, speaking on the condition of anonymity on Saturday in Washington, said the Pentagon has no indication so far that the Russian military has taken control of a Ukrainian city.

The heaviest fighting in Ukraine is currently around the northeastern city of Kharkiv, the U.S. official said, adding that the Russians are meeting stiff resistance against the northern advance toward Kyiv.

"This is very dynamic and will change hour by hour," the official cautioned, adding that the estimate is a "snapshot in time."

—Ted Kemp

Photos: Civil defense volunteers in Kyiv make Molotov cocktails

As Russian missiles pounded Ukraine's capital Kyiv on Saturday, volunteers from the city's Territorial Defense Units collected glass bottles and turned them into Molotov cocktails to use against the invading Russian troops. The Los Angeles Times' Marcus Yam made the pictures.

—Christina Wilkie

Elon Musk says Starlink satellite internet service becomes available in Ukraine

Mykhailo Fedorov, Ukraine's digital transformation minister, made a plea to SpaceX CEO and founder Elon Musk on Twitter early Saturday. He wrote, "While you try to colonize Mars — Russia try to occupy Ukraine! While your rockets successfully land from space — Russian rockets attack Ukrainian civil people! We ask you to provide Ukraine with Starlink stations and to address sane Russians to stand."

About 10 hours later, Musk replied in a tweet, "Starlink service is now active in Ukraine. More terminals en route."

Fedorov was quick to thank Musk and later expressed gratitude to Oksana Markarova, Ukraine's ambassador to the U.S., "for swift decisions related to authorization and certification that allowed us to activate the Starlink in Ukraine."

CNBC reached out to SpaceX for more details including who would foot the bill for terminals and Starlink satellite internet service provided in Ukraine, and whether Starlink could work for civilians taking cover in subways and bomb shelters underground.

By fulfilling the request of an Ukraine official, Elon Musk could strain SpaceX's relationship with Roscosmos. The Russian space agency has been working toward an agreement that would see Russia's Anna Kikina flying on a SpaceX Crew-5 mission in the second half of 2022. That mission is part of NASA's Commercial Crew Program, which allows public-private partnerships. As part of what is effectively a swap deal, CNBC previously reported, a NASA astronaut would be expected to fly on a future Soyuz mission.

—Lora Kolodny

Protests across the world continue to condemn Putin

People around the world have been standing up in protest of Russian President Vladimir Putin's continued attack on Ukraine. Here are photos from the past 24 hours:

—Adam Jeffery

EU, UK, Canada, US remove selected Russian banks from SWIFT system

The U.S. and its allies agreed to disconnect specific Russian banks from the Society for Worldwide Interbank Financial Telecommunication, or SWIFT, system.

SWIFT is an independent enterprise based in Belgium that serves as an internal messaging system between more than 11,000 banks and financial institutions in over 200 countries and territories.

"This will ensure that these banks are disconnected from the international financial system and harm their ability to operate globally," leaders from the U.S., European Commission, France, Germany, Italy, the United Kingdom and Canada wrote in a joint statement.

The retaliation means Russian banks won't be able to communicate securely with banks beyond its borders. Iran was removed from SWIFT in 2014 following developments to Tehran's nuclear program.

In addition, the group will impose restrictive measures aimed at preventing Russia's central bank from deploying its international reserves in ways that may undermine sanctions.

— Amanda Macias

Ukraine asks for cryptocurrency donations

Ukraine said on Saturday that it will accept direct cryptocurrency donations.

The country's Twitter account and its national digital minister, Mykhailo Fedorov, shared codes for people to donate bitcoin, ethereum and tether, three of the most popular digital coins.

The addresses posted by the Ukrainian government have received around $4.25 million in donations, according to data from blockchain analytics firm Elliptic. The firm said that includes a single donation worth $1.86 million that appeared to "have originated from the sale of NFTs originally intended to raise funds for Julian Assange." But the donation has nothing to do with Assange, Pak, an artist whom the WikiLeaks founder collaborated with on a non-fungible token entitled "Clock," told CNBC.

Previously, the Ukrainian Ministry of Defense has said it won't accept crypto donations directly. A statement on the government's website, still up as of Saturday afternoon, said that "national legislation does not allow the Ministry of Defense of Ukraine to use other payment systems ('Webmoney,' 'Bitcoin,' 'PayPal,' etc.)."

The Ministry of Foreign Affairs of Ukraine did not immediately respond to CNBC's request for comment.

Cryptocurrency enthusiasts appeared to rally around the cause after the Ukrainian accounts shared the codes. Justin Sun, founder of the Tron Foundation that led development of the Tron blockchain, posted a series of tweets in support of donations to Ukraine. Sun called on Ethereum co-founder Vitalik Buterin to donate, saying that he would match funds.

It comes after millions of dollars worth of crypto have been funneled to Ukrainian groups fighting against the Russian invasion.

This story has been updated to clarify that the links posted through Ukraine's account have received around $4.25 million in donations. Ukraine and NGOs providing support have raised $9.9 million, according to Elliptic.

—Jessica Bursztynsky

Putin has answered the West’s diplomacy with ‘tanks and steel,’ USAID’s Power says

Russian President Vladimir Putin has responded to calls for democracy "with tanks and steel," Samantha Power, administrator of the United States Agency for International Development, told CNBC.

"The only way to stave off human tragedy is a diplomatic solution. And certainly the Ukrainians have made very clear that that is what they are interested in," Power said in an interview with Steve Sedgwick.

—Jessica Bursztynsky

Germany supports restricting Russia from SWIFT bank-communication system

Germany has come out in support of restricting Russia from the world's primary bank-communication system, a move that would severely limit the ability of Russian companies to sell goods overseas or buy goods from abroad.

German Foreign Minister Annalena Baerbock said on Saturday that Berlin is working rapidly to restrict Russia from the system, known as SWIFT, in a targeted way that would limit collateral economic damage.

Baerbock's announcement marks a shift in German policy that makes SWIFT restrictions against Russia much more likely. Germany has been reluctant to sever Russia from SWIFT over concerns such a move would damage Germany's economy, which depends on Russian gas imports.

German Finance Minister Christian Lindner said on Friday that Berlin had already implemented an almost total blockade of Russian banks, but transactions were still possible to pay for gas deliveries, and so German companies could wire money to their subsidiaries in Russia. However, Lindner said all options were on the table.

SWIFT, which stands for the Society for Worldwide Interbank Financial Telecommunication, is an independent enterprise based in Belgium that serves as an internal messaging system between more than than 11,000 banks and financial institutions in over 200 countries and territories.

If Russia is excluded from SWIFT, it would mean Russian banks cannot communicate securely with banks beyond its borders. The only other country that has been expelled from SWIFT is Iran, whose oil exports declined afterward.

-- Spencer Kimball, Christina Wilkie

Germany will supply 1,000 anti-tank weapons and 500 stinger missiles to Ukraine

German Chancellor Olaf Scholz said the country will supply Ukraine with 1,000 anti-tank weapons and 500 stinger missiles, marking a reversal in Germany's arms-export policy.

"The Russian attack marks a turning point," Scholz said on Twitter. "It is our duty to do our best to help Ukraine defend against the invading army of Putin."

If a nation with reserves wants to transfer a weapon that originated in Germany, it has to ask Berlin for approval. Up until Saturday, the German government has held firm in its stance to restrict lethal weapons with German origin from being sent to conflict zones. That included Ukraine as Russian troops invaded and fired missiles.

However, the German government appeared to cede to pressure from its allies as Ukrainian officials put out calls for help.

"Keep it up, Chancellor @OlafScholz! Anti-war coalition in action!" Ukrainian President Volodymyr Zelenskyy wrote in a tweet.

—Jessica Bursztynsky

Russia has fired over 250 missiles at Ukraine since invasion began: U.S. defense official

A U.S. Defense Department official said Saturday that so far Russian forces have launched more than 250 missiles at Ukraine.

The official, who spoke on the condition of anonymity in order to share details from a Pentagon assessment, said the majority of the missile launches are a mixture of "short-range ballistic missile types." Soldiers are firing the missiles from both ground and naval-based platforms, the official said.

Ukraine's air and missile defense systems are still viable, even though some have been hit with strikes, the official said. The official declined to elaborate on the condition of Ukrainian military assets when pressed.

"I want to be careful here that we're not violating any Ukrainian operational security here," the official said.

The official said the next tranche of U.S. security assistance to Ukraine, which Secretary of State Antony Blinken announced earlier on Saturday, will include Javelin missiles. The Javelin weapon system, manufactured by defense giants Lockheed Martin and Raytheon, is a portable, shoulder-fired, medium-range anti-tank missile.

— Amanda Macias

Germany plans to approve delivery of lethal weapons to Ukraine, reports say

Germany is working to approve the delivery of 400 rocket-propelled grenades to Ukraine following pressure from Eastern allies, Reuters and Politico reported Saturday morning.

The German government will now allow the Netherlands to transport the RPGs to the Eastern European nation to fight off Russian invaders, Politico reported.

Countries aiming to send German-origin lethal weapons for export to Ukraine have to apply for approval. Up until Saturday, German officials had ruled out sending the lethal weapons to conflict zones.

The move marks a shift in how Germany is responding to the Russia's Ukraine invasion. Nations have mobilized to send guns, fuel and stingers to Ukraine as Russian troops pour in. But Germany's approval could lead to a rapid increase in military assistance, Politico reported.

Germany also said it would permit Estonia to send nine Soviet-made howitzers to Ukraine, according to the New York Times. Prior to Russia's invasion, Germany had blocked the transfer, citing its policy of sending weapons to tense regions.

Ukrainian officials have said they are in desperate need for arms and assistance from the country's allies. In a list shared with NATO, Ukraine leaders asked for items ranging from portable anti-aircraft missile systems and bulletproof helmets to bandaging equipment and machine guns, Politico said on Thursday.

—Jessica Bursztynsky

About half of the Russian forces along Ukraine's borders are now fighting inside the country, U.S. Defense official says

A U.S. Defense official said that approximately half of the Russian forces that were previously amassed along Ukraine's borders are now fighting inside the country.

The official, who spoke on the condition of anonymity, declined to comment further on Russia's force posture outside of Ukraine.

The official also said that the Pentagon has no indication thus far that the Russian military has taken control of any Ukrainian cities. The person said Russia's "momentum continues to be slowed predominantly from a stiff Ukrainian resistance."

The Defense official said that the heaviest fighting is currently ongoing in the northeastern city of Kharkiv and near Kyiv. The person said that the Pentagon estimates that Russian forces are approximately 30 kilometers, or about 18 miles, north of Kyiv.

"This is very dynamic and will change hour by hour," the official cautioned.

—Amanda Macias

U.S. State Department sends $350 million and more firepower for Ukraine fight

U.S. Secretary of State Antony Blinken authorized an additional $350 million for Ukraine as the country faces brutal attacks from neighboring Russia and Belarus.

"This package will include further lethal defensive assistance to help Ukraine address the armored, airborne, and other threats it is now facing," Blinken wrote in a Saturday statement. "This brings the total security assistance the United States has committed to Ukraine over the past year to more than $1 billion," the nation's top diplomat added.

Last fall, amid a steady Russian troop buildup along Ukraine's borders, the Pentagon authorized $60 million in immediate military assistance to Ukraine. In December, as the Russia threat materialized, Blinken authorized another package worth $200 million.

State Department spokesman Ned Price also announced Saturday that the Pentagon will immediately provide Ukraine with further defensive support, including anti-tank and air defense capabilities. On Friday, Pentagon spokesman John Kirby said the U.S. was determining the best way to deliver additional support to Ukraine, citing logistics issues amid the armed conflict.

"We are going to provide additional security assistance for Ukraine. We will. How that is going to be done is still being worked out," Kirby said, adding: "The airspace over Ukraine is contested."

—Amanda Macias

Nearly 120,000 Ukrainians have fled, U.N. refugee agency says

The U.N.'s refugee agency said Saturday that nearly 120,000 Ukrainians have fled the country since the start of the Russian invasion, according to the Associated Press.

"Almost 116,000 have crossed international borders as of right now. This may go up, it's changing every minute," Shabia Mantoo, spokeswoman for the U.N. High Commissioner for Refugees, told the AP.

That number is quickly rising, as people frantically grab their belongings and flee while Russian troops fire off bombs and missiles. Most refugees have sought shelter in Poland and other neighboring countries.

The Polish government said early Saturday more than 100,000 Ukrainians had crossed the Polish-Ukrainian border in the past two days. Other refugees have headed to Moldova, Hungary, Romania, Slovakia and Belarus, according to the AP.

The agency has said up to four million Ukrainians could evacuate if conditions continue to worsen.

Since the start of the Russian invasion, 198 Ukrainians have died, including three children, with 1,115 wounded, including 33 children, Ukraine's Minister of Health Oleh Liashko said on Facebook.

—Jessica Bursztynsky

Melitopol capture disputed

The current status of the southern Ukrainian city of Melitopol is being disputed after Russia's defense ministry claimed its forces had captured it.

A video posted to social media appeared to show a Russian flag flying above a police station in Melitopol. However, James Heappey, a British armed forces minister, told the BBC Saturday that Russian forces had failed with their objective.

"We can't see anything to substantiate" the claim, he said.

—Matt Clinch

Kyiv mayor extends curfew

Kyiv Mayor Vitaly Klitschko has extended the city's curfew from 5 p.m. to 8 a.m. with the aim of further protecting its citizens from the Russia attack.

He warned on Twitter: "All civilians who will be on the street during the curfew will be considered members of the enemy's sabotage and reconnaissance groups."

—Matt Clinch

Facebook prohibiting Russian state media from running ads

Facebook said overnight that it was now prohibiting Russian state media from running ads or monetizing on its platform.

The Russian government, meanwhile, has accused Meta's Facebook of "censoring" Russia media and has partially limited access to the platform in the country.

—Matt Clinch

Russian vessel seized in the English Channel

France on Saturday intercepted a Russian vessel in the English Channel in line with new EU sanctions against Moscow, according to multiple media reports.

The cargo ship was bound for St. Petersburg and was transporting cars, but French sea police redirected the vessel to the port of Boulogne-sur-Mer in northern France.

Read more here.

—Matt Clinch

Zelenskyy says attacks have been repelled

President Volodymyr Zelenskyy posted another video message on his social media account on Saturday saying that his military had successfully repelled enemy attacks overnight.

Zelenskyy, who is still in Kyiv, spoke in Russian and directed his comments to the Russian military.

"Thousands of victims, hundreds of prisoners who simply cannot understand why they were sent to Ukraine, sent to Ukraine to die, kill others. The sooner you tell your authorities that the war must be stopped immediately, the more of your people will remain alive," he said, according to an NBC translation.

—Matt Clinch

Ukraine minister of health: 198 Ukrainians have died since start of invasion

Ukraine's Minister of Health Oleh Liashko gave an update via Facebook on the current death toll in the country.

He said, according to an NBC News translation, that since the start of the Russian invasion, 198 Ukrainians have died, including three children, with 1,115 wounded, including 33 children.

—Matt Clinch

Photos show damage to high-rise apartment block in Kyiv

The below images from Getty show the Kyiv apartment building damaged by what the Ukrainian government says were Russian missiles.{=null}

—Matt Clinch

'No Russian troops in the capital,' says Kyiv mayor

Vitali Klitschko, Kyiv's mayor, posted a video on Telegram giving a figure on the overnight casualties in the city.

"The night was difficult, but there are no Russian troops in the capital," he said, according to a NBC translation.

"The enemy is trying to break into the city, in particular, from Hostomel, Zhytomyr. The aggressor was neutralized there. Now, unfortunately, SRGs are operating in Kyiv. As of the 6 a.m. in the morning there are 35 injured people, including 2 children."

—Matt Clinch

Kyiv apartment building damaged

A Kyiv apartment building has been damaged by what the Ukrainian government says were Russian missiles.

Ukraine's Minister for Foreign Affairs Dmytro Kuleba tweeted: "Kyiv, our beautiful, peaceful city, has spent another night under attack by Russian ground forces and missiles. One of them hit an apartment building in Kyiv," according to an NBC translation.

NBC News has not been able to verify the allegation by Kuleba and information about any casualties is still being gathered.

—Matt Clinch

Ukraine President Zelenskyy denies he has called for surrender

Ukrainian President Volodymyr Zelenskyy posted a video on his Twitter feed early Saturday denying claims that he has called his army to stand down.

"There is a lot of fake information online that I call our army to put down arms and there is evacuation going on," he said, according to an NBC translation.

"I'm here. We won't put down [our] weapon, we'll protect our country because our weapon is our truth and it is our land, our country, our children and we will defend all of it. That's it. That's what I wanted to tell you. Glory to Ukraine."

—Matt Clinch