Armed gunmen attacked the compound on Tuesday evening, clashing with Libyan security forces before the latter withdrew as they came under heavy fire. The armed group is said to have been protesting a film being produced in the United States.
The incident followed a protest in neighboring Egypt where demonstrators scaled the walls of the U.S. embassy, tore down the American flag and burned it during a protest over what they said was a film that insulted Prophet Mohammad.
Reuters reporters on the scene could see looters raiding the empty Benghazi compound, walking off with desks, chairs and washing machines.
Unknown gunmen were shooting at the buildings while others threw handmade bombs into the compound, setting off small explosions. Small fires were burning around the compound.
Passersby entered the unsecured compound to take pictures with their mobile phones and watch the looting.
No security forces could be seen around the consulate and a previous blockade of the road leading to it had been dismantled.
"The Libyan security forces came under heavy fire and we were not prepared the intensity of the attack," Hurr said.
Libya's interim government has struggled to impose its authority on a myriad of armed groups which have refused to lay down their weapons and often take the law into their own hands.
A number of security violations have rocked Benghazi, Libya's second biggest city and the cradle of last year's revolt that toppled Muammar Gaddafi.
