Suspected US-led coalition air strikes have killed 11 civilians, mostly children, in a jihadist-held village in northern Syria, a monitor said Friday.

"Eight children and three women were killed in strikes by the international coalition on Hazima, a village north of Raqa city" on Thursday, said Rami Abdel Rahman, head of the Syrian Observatory for Human Rights.

Hazima is held by the Islamic State jihadist group, but a Kurdish-Arab rebel alliance has been fighting to capture it since late December.

That alliance, the Syrian Democratic Forces, works closely with the US-led coalition and calls in aerial raids.

The Britain-based Observatory has an extensive network of sources inside Syria.

The coalition, Russia and the Syrian air force are all carrying out air raids in the country, but the Observatory differentiates between strikes based on the type of aircraft flown and the munitions used.

The monitor said on December 23 that coalition air raids had killed a total of 299 civilians, including 81 children, and about 3,700 IS members.

The coalition has been conducting strikes in Syria since September 2014, but has rarely acknowledged civilian deaths in its campaign there and in neighbouring Iraq.

In November, it said four civilians, possibly including a child, had "likely" been killed in a strike in Iraq in March.

And a year earlier, it acknowledged it killed two children in a strike in Syria.

Late Thursday, the Syrian Democratic Forces said in a statement it was engaged in "violent clashes" with IS in Raqa province, a bastion of the jihadist group in Syria.

The jihadists were fighting to retake Ain Issa, a town lying at a strategic crossroads that Kurdish and Arab rebel groups captured last year.

More than 260,000 people have been killed since Syria's conflict erupted in March 2011.