FILE – In this Friday, Sept. 21, 2012 file photo, a Syrian boy shouts slogans against the regime in front of a flag of the armed Islamic opposition group, the Nusra front, during a demonstration in the Bustan al-Qasr neighborhood of Aleppo, Syria. Activists said on Saturday, July 13, 2013 that Syrian rebels and fighters from an al-Qaida-linked group have turned their guns on each other and are fighting for control of a key checkpoint in the northern city of Aleppo. The checkpoint is the only gateway between rebel-held eastern districts and the city’s western areas, controlled by President Bashar Assad’s troops. Arabic on banner in background contains words from the Quran and reads, “There is not God but Allah, and Muhammad is his messenger, the Nusra front” (AP Photo/ Manu Brabo, File)