On Sunday, unknown assailants fired a rocket-propelled grenade at a Benghazi police compound, which houses patrol cars, damaging an office and killing one policeman. A gun battle followed and three of the police reinforcements who arrived at the scene were killed, a police spokesman said. That attack is believed to be linked to the recent detention of two men in connection with several assassinations of security officials in the city, as the assault happened next door to a police station where they were being held. http://www.reuters.com/article/2012/12/17/us-libya-attack-benghazi-idUSBRE8BG01E20121217
It wasn't a coordinated attack, there were a bunch of protestors who sighted one of those wacky kitten videos on youtube. Hillary said so.