A US official has been killed and others wounded after militiamen stormed the US consulate in the Libyan city of Benghazi, security officials say.
It is believed the protest was held over a US-produced film that is said to be insulting to the Prophet Muhammad.
The building is said to have burnt down after being set alight by protesters. It is thought nobody was in the consulate at the time.
Protests have also been held at the US embassy in the Egyptian capital, Cairo.
Witnesses say the protest in Benghazi prompted a confrontation between government security forces and an armed militia known as the Ansar al-Sharia brigade, the BBC's Rana Jawad in Tripoli reports.
"One American staff member has died and a number have been injured in the clashes," Abdel-Monem Al-Hurr, spokesman for Libya's Supreme Security Committee, told Reuters news agency.
The identity of the US official killed is not yet known.
The US said it condemned the attack "in the strongest terms" and was working with Libyan security forces to secure the compound, a statement by US state department spokeswoman Victoria Nuland said.
The film that sparked the demonstration is said to have been produced by some Egyptian Copt expatriates. A trailer of it has appeared on YouTube in Arabic.
More at http://www.bbc.co.uk/news/world-africa-19562692
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