The US ambassador to Libya, Chris Stevens, was killed on 11 September in what appeared to be an organised and well-armed attack on the US diplomatic mission in Benghazi, Libya's second city.

Stevens, who had served as ambassador to Libya since January 2012, is believed to have died from smoke inhalation. Three other Americans were killed in the assault, as were an unconfirmed number of Libyans. 

At the time of writing on 13 September, many details of the attack remained unclear. One possibility is that a demonstration outside the US consulate, held to protest against an inflammatory anti-Islamic film, may have spontaneously escalated into an armed assault.

Another, perhaps more likely scenario involves a pre-planned assault that was unrelated to the film and carried out by a well-organised group of Islamic militants. On the same day as the incident, which fell on the 11th anniversary of the 9/11 attacks, Al Qaeda leader Ayman al Zawahiri issued a message urging Libyans to avenge the death of Abu Yahya al-Libi, a senior Libyan commander in Al Qaeda, who was killed by a US drone strike in Yemen in June this year.

The White House said it had dispatched 50 Marines to Libya to help find the perpetrators of the attack, emphasising that it would work together with the Libyan government in bringing those responsible to justice.

The leader of Libya's national assembly, Mohamed Magarief, apologised for the incident and promised to protect all foreigners in the country.