BEIRUT (AP) -- Syrian activists say a string of government airstrikes on rebel areas in the country's north has killed at least 20 people, leveled buildings and forced residents to dig through mounds of rubble in search of survivors.
The activists say the strikes happened late Wednesday and early Thursday and hit a total of four towns in Idlib and Aleppo provinces.
They say residents are searching through the rubble in some of the towns, while in others the dead were buried before being identified.
Videos of the strikes posted online show leveled buildings and survivors pulling bodies from the debris.
Activist claims and videos could not be independently verified.
President Bashar Assad's forces have increasingly relied on air power as the rebels have improved their fighting capabilities on the ground.