Seven civilians, including a woman and a child, were killed on Thursday when abandoned ammunition exploded inside a house in Idlib province in northwestern Syria.
The information comes from the British-based Syrian Human Rights Observatory (SOHR).
The incident occurred a day after a report was released showing that two-thirds of Syrians are at risk of being killed or injured by unexploded ammunition.
The civil war in Syria has killed more than half a million people and forced millions from their homes since it broke out in 2011.
