** FILE ** A Syrian walks by a building destroyed in an airstrike in Aleppo, Syria, on Friday, Aug. 17, 2012. The growing use of air power by the Syrian regime has caused a spike in civilian casualties, activists say. (AP Photo/Khalil Hamra)

Photo by: Khalil Hamra

** FILE ** A Syrian walks by a building destroyed in an airstrike in Aleppo, Syria, on Friday, Aug. 17, 2012. The growing use of air power by the Syrian regime has caused a spike in civilian casualties, activists say. (AP Photo/Khalil Hamra)