A picture shows the main entrance of the US consulate compund in Benghazi on September 13, 2012, following an attack on the building late on September 11 in which the US ambassador to Libya and three other US nationals were killed. Libya said it has made arrests and opened a probe into the attack, amid speculation that Al-Qaeda rather than a frenzied mob was to blame. AFP PHOTO/GIANLUIGI GUERCIA        (Photo credit should read GIANLUIGI GUERCIA/AFP/GettyImages)