U.S. ambassador to Libya Chris Stevens and three other embassy staff were killed in an attack Tuesday on the U.S. Consulate in the eastern Libyan city of Benghazi, Reuters reported citing a Libyan official.

Al Jazeera reported that Stevens died from smoke inhalation in the rocket attack while Reuters said it was not clear if he was in his car or inside the consulate building when the attack occurred.

The attack on the consulate followed fierce clashes between Libyan security forces and armed mob near the embassy premises over a film, titled "Innocence of Muslims" directed by California-based Sam Bacile. The film is alleged to be offensive to Islam and Prophet Muhammad.

Egypt's capital Cairo also witnessed similar protests Tuesday.

Stevens was the U.S. representative to the Transitional National Council in Benghazi during the revolution.