What caused the deadly explosion at a Gaza hospital? The US says Israel is not to blame

A deadly explosion at the Christian-run Ahli Arab Hospital hospital in central Gaza this week killed 471 people, according to the Palestinian Health Ministry.

There have been conflicting claims about who was responsible for the explosion. Hamas officials in Gaza quickly blamed an Israeli airstrike. But Israel denied it was involved and said the blast was instead due to a rocket misfire by another militant group operating in Gaza.

Neither side’s account could be immediately independently verified, and the precise death toll remained unclear.

Here is what to know about the accusations surrounding the explosion at a Gaza hospital.

What do U.S. officials say?

On Wednesday afternoon, White House National Security Council spokesman Adrienne Watson told NBC News that "the U.S. government assesses that Israel was not responsible for an explosion that killed hundreds of civilians yesterday at the Al Ahli Hospital in the Gaza Strip."

"Our assessment is based on available reporting, including intelligence, missile activity, and open source video and images of the incident," Watson said.  

President Joe Biden, on a visit to Tel Aviv, said data from his Defense Department showed that the explosion was not likely caused by an airstrike by the Israeli military.

Officials told the New York Times that U.S. intelligence agencies have analyzed open-source video of the launch showing that it did not come from the direction of Israeli military positions.

Still other U.S. officials, who spoke to the New York Times on the condition of anonymity, cautioned that the analysis was preliminary and that they were continuing to collect and analyze evidence.

What do Israeli officials say?

Israel quickly denied it was involved and released a flurry of video, audio and other information that it said showed the blast was instead due to a rocket misfire by Palestinian Islamic Jihad.

In a briefing with reporters, the Israel Defense Forces chief army spokesman, Rear Adm. Daniel Hagari, said the army determined there were no air force, ground or naval attacks in the area at the time of the blast. He said radar detected outgoing rocket fire at the same moment, and intercepted communications between militant groups indicated that Islamic Jihad fired the rockets.

Hagari also shared aerial footage collected by a military drone that showed a blast that he said was inconsistent with Israeli weaponry. He said the explosion occurred in the building's parking lot, and he noted that the death toll could not be confirmed.

What does Hamas say?

Hamas, which the U.S. State Department designated a terrorist group in 1997, is the Palestinian governing body in the Gaza Strip, and it called the hospital blast “a horrific massacre.” It said it was caused by an Israeli strike and denied claims that another militant group was responsible. 

Hamas said that Israel had sent warnings to hospitals calling for them to evacuate as part of their military operation and that since “the beginning of this aggression, the Israeli army has ignored the principle of distinguishing between civilian and military targets.”

Hamas also said “resistance missiles are homemade, and do not have the destructive power that kills hundreds at once.”

In a statement Wednesday, Hamas said that in the days before Tuesday's blast Israeli authorities contacted several Gaza Strip hospitals and told each to evacuate otherwise “they will be responsible for what happens.”

The Israeli military has acknowledged that in recent days it called Ahli Arab hospital as part of a wider effort to encourage residents to move southward as it prepared for a broader invasion, according to the New York Times. The military did not call the hospital to warn of a specific strike on the hospital, said Lt. Col. Amnon Shefler, a military spokesman.

What is Palestinian Islamic Jihad?

Palestinian Islamic Jihad is a smaller, more radical Palestinian militant group that often works with Hamas. It has dismissed claims that it was responsible for the hospital explosion.

Photos: Israel-Hamas War