US ambassador to Libya and three other diplomats were killed in a furious attack on their consulate and a safe house in the eastern city of Benghazi by Islamist gunmen blaming America for a film they said insulted the Prophet Mohammad.
The US embassy in Egyptain capital Cairo, too, bore the brunt of rioters' anger over the film made by an Israeli filmmaker living in the US.
California-born ambassador Christopher Stevens, an old Arab hand, had gone to the consulate in Benghazi, the cradle of last year's uprising against Muammar Gaddafi's 42-year rule, with the others to evacuate it after it came under attack Tuesday. It was not clear how or where Stevens died.
The US consular staff were rushed to a safe house after the initial attack, Libya’s deputy interior minister Wanis Al-Sharif said. An aircraft with US commandos then arrived from Tripoli to evacuate them.
“It was supposed to be a secret place and we were surprised the armed groups knew about it,” he said, adding two US personnel were killed there.
US pastor Terry Jones, who had inflamed anger in the Muslim world in 2010 with plans to burn the Quran, said he had promoted the film.
"While the United States rejects efforts to denigrate the religious beliefs of others, we must all unequivocally oppose the kind of senseless violence that took the lives of these public servants," said President Barack Obama.
A US Marine counterterrorism team has been dispatched to Benghazi, reflecting suspicions that a terrorist group may have used the rioters as a shield to target Stevens. The ambassador was supposedly killed by a rocket-propelled grenade -- a weapon normally used by a trained soldier.
The killings have raised questions about the stability of the Libyan regime, which has struggled to contain scores of local militias, and whether more protests might erupt in the Muslim world over the film.