At least 39 people, including 12 children, have been killed in a blast that brought down a building in the mainly rebel-held Syrian province of Idlib.
The building in the town of Sarmada is said to have been an arms depot belonging to a trafficker.
A member of the Idlib civil defence team said that "buildings full of civilians were reduced to rubble". Rescuers used bulldozers to remove the debris and pull out trapped people.
The Syrian Observatory for Human Rights said dozens are still missing.
The cause of the explosion has not been reported.
Idlib is Syria's last major rebel-held area and is expected to be the next target for Syrian armed forces.
In recent months, the regimem backed by Russia and Iran, has made major advances against rebel and jihadist groups across the country.