This undated image posted on Wednesday, Aug. 27, 2014 by the Raqqa Media Center, a Syrian opposition group, which has been verified and is consistent with other AP reporting, shows a fighter from the Islamic State group, armed with a knife and an automatic weapon, next to captured Syrian army soldiers and officers, following the battle for the Tabqa air base, in Raqqa, Syria. (AP Photo/Raqqa Media Center)