• Flights were resuming on Sunday after airspace closures grounded some Middle East flights late Saturday.
• Israel and Jordan were among the countries that closed airspace as Iran launched a drone strike on Israel.
• Iran had said it would retaliate against Israel for a airstrike on the Iranian consulate in Damascus.

Airspace reopened allowing flights throughout the Middle East to resume on Sunday, but dozens of others were canceled after Iran attacked Israel with drones and missiles overnight after a suspected Israeli strike in Syria earlier this month that killed several top Iranian officials.

Israel's El Al canceled more than 20 Sunday flights, though some were still operating. Two El Al flights headed for Israel from Thailand on Saturday had diverted to Bangkok. The carrier told passengers not to come to the Tel Aviv airport until notified.

Emirates Airline canceled one of its Dubai-Amman flights which was scheduled for Sunday, but flew two others. Air France and British Airways canceled Tel Aviv flights on Sunday. British Airways also scrubbed a flight to Amman.

Lufthansa canceled its service to and from Tel Aviv, Erbil, Iraq and Amman through Monday and plans to resume service on Tuesday, though its Beruit and Tehran flights are suspended until at least Thursday, it said.

Some flights avoided large swaths of airspace in the Middle East, reroutes that delayed some planes, Swiss International Airlines said.

The reroutes are the latest challenge for airlines that in recent years have had to change flight plans in the wake of Russia's attack on Ukraine, which can add to flight time and fuel costs.

United Airlines, which resumed service to Tel Aviv early last month after suspending Israel flights after the Hamas attacks in October, called off its Newark to Tel Aviv flights on Saturday and Sunday after Israel briefly closed its airspace. Jordan, Lebanon and Iraq had also closed their airspace.

"We are closely monitoring the situation and will make decisions on upcoming flights with a focus on the safety of our customers and crews," United said in a statement. The carrier is the only U.S. airline to have resumed service to Israel since October.

United's Monday departure from Newark to Tel Aviv was listed as scheduled as of Sunday afternoon.

Delta was scheduled to restart flights to Tel Aviv on June. 7. American Airlines has not resumed Israel flights. The carrier canceled its Philadelphia-to-Doha flight on Saturday, but the Sunday departure was still scheduled.

United also canceled its flights from Washington Dulles International Airport to Amman, Jordan, on Saturday night and from Newkark to Dubai "due to unrest in the Middle East." However, the Dubai departure was still listed as scheduled for Sunday.

Flight-tracking site Flightradar24 said multiple flights bound for Tel Aviv and Amman had diverted on Saturday.