|US embassy in Libya|
Barack Obama dispatched 50 US marines to Libya to help hunt down the killers of American ambassador Chris Stevens as suspicions grew that the attack was planned and carefully orchestrated.
The president vowed that "justice will be done" after Mr Stevens, 52, was killed by an Islamist mob in an attack on the US consulate in the eastern coastal city of Benghazi. Three other Americans were also killed in the raid, which came on the anniversary of September 11.
However, there was mounting speculation that the attack on the Benghazi consulate, which also killed a second diplomat, Sean Smith, and two other US officials, had been carefully planned by al Qaeda linked Islamic extremists.
The attackers were apparently armed with mortars and rocket propelled grenades, while there was speculation of links with the death of al Qaeda's deputy leader or the 11th anniversary of the terrorist attacks on New York and Washington.
A grenade had set a building inside the walled consulate compound ablaze, leaving the Americans facing both a fire inside and attackers outside.
Mr Stevens and the others who died tried to escape to the roof of the building and succumbed to smoke inhalation.
Doctors at the Benghazi Medical Center said Mr Stevens had been at the point of death when he was brought into the facility by several friendly Libyans. "We tried to revive him for an hour and a half but with no success.