MERTISMAIL, Turkey — Islamic State militants swept into a Kurdish village in Syria on Wednesday just across the border from this Turkish hamlet, as farther south, in the western Syrian city of Homs, twin car bombs killed at least 45 people, including 41 children, according to the Syrian Observatory for Human Rights, an antigovernment monitoring group.

There was no immediate claim of responsibility for the bombings. Video posted online showed people running and shrieking amid black smoke, and sidewalks littered with body parts, before a second explosion went off.

The bombs struck near an elementary school in Akrama, a district that is home to many government supporters and has been targeted before by jihadist groups like the Nusra Front. Militants from the Islamic State, also known as ISIS, have recently increased their presence in Homs Province as well.

Across the country, the conflict continues among Syrian insurgents, the Islamic State and the government, which has continued bombarding opposition-held areas. The Syrian Network for Human Rights said Wednesday that in September alone, 2,375 people had died in the conflict; of those, more than 1,700 were killed by government forces, among them 294 children.