Article Photos: Rebels attack sprawling air base in northern Syria 1/2

This image taken from video obtained from Ugarit, which has been authenticated based on its contents and other AP reporting, shows an explosion during heavy fighting between rebels and Syrian government forces in the Barzeh district of Damascus, Syria, Friday, April 26, 2013. On the streets of Damascus, the two-year old conflict dragged on Friday, with government troops pushing into two northern neighborhoods, triggering heavy fighting with rebels as they tried to advance under air and artillery support, activists said. The Britain-based Syrian Observatory for Human Rights said the fighting between rebels and soldiers backed by pro-government militiamen was concentrated in the Jobar and Barzeh areas.(AP Photo/Ugarit via AP video)