Syrian rebels stepped up their siege of a government helicopter base near Aleppo on Friday, following news that a regime airstrike on a northern town had left 14 dead—the majority of whom were women and children. This is the fourth airport the rebels have surrounded in the last few days, as they reportedly pummel soldiers inside with mortars, homemade rockets, and sniper fire. The moves are key in the ongoing effort to strip power from President Bashar al-Assad, who relies heavily on airstrikes to block rebels. As the civil war rages into its 21st month, the international peace envoy to Syria is calling for the formation of a transitional government to run the country until elections can be held.
AIR FORCE Shaam News Network/AP via AP Video