The US ambassador to Libya has died after an attack by militiamen on the US consulate in the eastern city of Benghazi, reports say.
Ambassador Christopher Stevens is said to be among four US officials killed in a protest over a US-produced film that is said to insult the Prophet Muhammad.
The US state department has only confirmed the death of one official - but it has not named them.
Protesters have also attacked the US embassy in Cairo over the film.
In the attack in Benghazi, unidentified armed men stormed the grounds, shooting at buildings and throwing handmade bombs into the compound.
Security forces returned fire but Libyan officials say they were overwhelmed.
A Libyan official has said Ambassador Stevens died from suffocation as a result of the attack.