Syria's air force carried out air strikes on Sunday on Douma city, an insurgent stronghold **rtheast of Damascus, with 18 people killed and at least 100 wounded including children and other civilians, the Britain-based Syrian Observatory for Human Rights said. Overnight, Syria's military killed dozens of combatants in southern Syria linked to al Qaeda's Nusra Front including three senior members, state media reported. Eastern areas are dominated by the ultra-radical Islamic State group which is also fighting Kurdish forces in the **rth. The Observatory said more than 215,000 people have been killed since the start of the crisis in March 2011, around half of them civilians.