They said the raids targeted a medical center, a school and a residential area in Jayrud town, a heavily populated area that struck a local truce with the army that had spared it the heavy bombing on other rebel held areas. It had made it a sanctuary for thousands of civilians fleeing heavy battles nearby.
The UK-based Syrian Observatory for Human Rights said scores were also injured in the aerial strikes as well as shelling from army posts in the area.
A rebel spokesman said the strikes seemed to be in revenge for the killing of a Syrian air force pilot who parachuted down near the town after his plane crashed on Friday.