A car bomb exploded on the outskirts of a northern Syrian city on Monday, killing at least 19 people, all but one of them women, and leaving more than a dozen wounded, hospital workers said.

The car detonated next to a vehicle carrying mostly female agricultural workers on the outskirts of the city of Manbij.

The dead included 18 women and one man, a nurse at the hospital, Mohammad Ahmad, told The Associated Press. Another 15 women were wounded, some of them in critical condition, according to the local Syrian civil defence.

No group immediately claimed responsibility for the explosion.

It was the seventh car bomb explosion in Manbij in just over a month, said Munir Mustafa, the deputy director of civil defence.

Manbij in northeastern Aleppo province continues to witness violence even after the downfall of President Bashar Assad in December.

Turkish-backed factions, known as the Syrian National Army, have clashed with the US-backed Kurdish-led Syrian Democratic Forces. The factions took the city from the SDF in early December during a lightning insurgency that toppled President Bashar Assad.

A resident said the car that detonated was parked on the roadside.