An attack on a bus early on Monday morning in northern Syria has killed 13 people, most of them government troops, the country's defence ministry said.
A ministry statement said that 11 government troops and two civilians were killed in what it said was a terrorist attack on a civilian transit bus. It said another three soldiers were wounded.
Syrian state news agency SANA said the attack took place in the Jabal al-Bishri region of the vast province of Raqqa.
The Syrian Observatory for Human Rights said the ambush had been carried out by Islamic State sleeper cells that launch hit-and-run attacks in the country's desert areas.
There was no immediate claim of responsibility for the attack.
Syria's 11-year-old conflict has carved the country into various zones of control, with government troops and allied fighters controlling the most territory.
A patch of northwestern territory is held by Turkish-backed rebels and more hardline groups while Kurdish-led forces with U.S. backing hold the northeast.
One of the deadliest bus ambushes was in December 2020, when 28 people were killed in an attack on a main highway in Syria's eastern Deir al-Zor province.
(Reporting by Kinda Makieh and Omar Fahmy, Writing by Maya Gebeily, Editing by Gareth Jones, William Maclean)
