A mysterious blast in Syria's north has killed at least 36 people, including children, opposition activists said.
The blast occurred in the village of Sarmada near the Turkish border, killing 36 people and wounding many others, according to the opposition-run Syrian Civil Defence, first responders also known as the White Helmets.
It said the explosion collapsed two five-storey buildings, burying many of the victims.
The Britain-based Syrian Observatory for Human Rights put the death toll at 39, including 21 women and children.
The observatory said an arms depot in the basement of a building exploded.
It said the depot was run by an arms dealer close to the Levant Liberation Committee, an al Qaida-linked group.
The observatory said many of the residents killed were displaced earlier this year from the central province of Homs.