US-led air strikes targeting the Islamic State group killed at least 52 civilians in a village in northern Syria, a monitoring group said on Saturday.

"Air strikes by the coalition early on Friday on the village of Birmahle in Aleppo province killed 52 civilians," said Rami Abdel Rahman, head of the Syrian Observatory for Human Rights.

"Seven children were killed, and 13 people are still trapped in the rubble," he said.

Abdel Rahman told AFP that Kurdish militiamen and Syrian rebel fighters were clashing with IS in a town roughly two kilometres (1 mile) away.

"But Birmahle is only civilians, with no IS positions and no clashes," he said.

Abdel Rahman said "not a single IS fighter" was killed in the strikes on the village, but that raids on a nearby town had killed at least seven jihadists.

Air strikes by the US-led coalition have supported Kurdish militias fighting the jihadists in Aleppo province, most notably in the flashpoint border town of Kobane, which is near Birmahle.

Backed by the strikes, Kurdish fighters drove IS out of Kobane in January.

A statement released on Friday by the joint task force for the anti-IS coalition said it had conducted six air strikes near Kobane on IS tactical units.

Prior to Friday's strikes, the coalition's raids had killed 66 civilians since it began attacking IS positions in Syria in September 2014.

According to the Britain-based Observatory, the air campaign has killed more than 2,000 people in total, including at least 1,922 IS fighters.