Top U.S. security officials are now calling the killings at the U.S. consulate in Benghazi on September 11th a terrorist attack.
But what remains under debate is whether that attack was planned or spontaneous.
A group with ties to Al Qaeda is claiming responsibility for last week's attack on the U.S consulate in Libya.
The September 11th attack killed U.S. Ambassador Chris Stevens and three other Americans.
Sources who are familiar with extremist groups say members of the banned Omar Abdul Rahman Brigades were behind the assault on the embassy.
Experts say the group used the pretext of an inflammatory online video depicting the Islamic Prophet Mohamed to launch the attack.