Syrian activists say strikes by the U.S.-led coalition against the Islamic State (IS) group have killed at least 15 civilians, including three children, in northeastern Syria.
The British-based Syrian Observatory for Human Rights said the strikes hit four IS-controlled villages in Hasakeh Province on February 18.
The Britain-based monitor said nine IS fighters also died in the strikes on the villages.
It said the latest civilian casualties brought to 38 the number of civilians reported killed in U.S.-led strikes in Hasakeh since February 16.
The coalition has reportedly stepped up its raids in the province since Syrian Kurdish fighters launched this week an operation against IS militants in the southern part of the province.
The observatory said last month that the coalition campaign had killed some 332 civilians in Syria since it began, including 90 children.