rewrite this title Car Bomb in Syria Kills 15 Agricultural Workers

A car bomb killed 15 agricultural workers in northern Syria on Monday, the country’s civil defense force said, as ongoing violence threatens to undermine the new government’s push for stability.

There were no immediate claims of responsibility for the explosion, which took place in the city of Manbij, about 20 miles from the border with Turkey. Manbij has been a focal point of violence between armed groups, one backed by the United States and the other by Turkey. The blast on Monday was one of the deadliest such attacks since the fall of Bashar al-Assad in December.

The Turkish-backed fighters wrested control of the city in December from Kurdish-led forces, who are supported by the United States, and there has since been a spate of car bombings, according to the White Helmets, the Syrian civil defense force.

The agricultural workers were being transported in the back of a truck when a car bomb exploded alongside them on the outskirts of the city, which lies about 55 miles northeast of Aleppo, the White Helmets said in a statement.

Most of the dead were women. At least 15 other people were wounded, and the death toll was expected to rise, the force said.

Footage from the aftermath showed the charred and mangled remnants of a vehicle, and the truck carrying the workers was pierced with shrapnel.

The continued violence underscored the challenges faced by Syria’s new interim president, Ahmed al-Shara, who is attempting to navigate a critical juncture in the country’s history.

Mr. al-Shara, who was appointed last week, has pledged to create an inclusive transitional government. To that end, the new authorities have announced the dissolution of all armed factions in the rebel coalition that toppled Mr. Assad, the country’s longtime dictator.

It remains unclear, however, whether armed groups that have so far refused to give up their weapons — including the Kurdish-led forces who control most of northeastern Syria — will eventually accept that mandate.

Unifying Syria’s complex web of armed groups under a single umbrella, experts say, is among the most pressing challenges facing the new government.