The first American service members to die in the U.S.-Israeli war with Iran were killed in an apparent Iranian drone attack on a makeshift office space in Kuwait, sources told CBS News.

"We're also learning that U.S. service members in Kuwait really had no opportunity to take cover before the makeshift operations center that they were in took a direct hit"

The US defence secretary confirms a US military base was hit by an Iranian missile on Sunday.

Separately, a drone attack hit the U.S. Embassy compound in the Persian Gulf state, as Iran continues to target American assets across the Middle East.

Photos show US pilot being rescued after apparently ejecting over Kuwait - as smoke seen rising near the US embassy

KUWAIT CITY, March 2 (Reuters) - Kuwait's ⁠air ⁠defences mistakenly shot down three U.S. F-15 ⁠fighter jets during active combat on Monday, U.S. Central Command said on Monday, describing it as an ​apparent friendly-fire incident during the conflict with Iran.

The State Department also ordered nonessential staff in the United Arab Emirates, Qatar, Bahrain, Jordan and Iraq to to leave amid further retaliation from Iran.

The incident that occurred late on Sunday was confirmed by top Pentagon officials during a Monday press conference.

About 45 minutes into the journey, the pilot announced that Iraqi airspace had been abruptly shut, forcing the aircraft to return to Kuwait.