At least 22 civilians were killed in a triple suicide car bomb attack in northeastern Syria on Thursday night, a monitor said Friday in a revised toll.
The Syrian Observatory for Human Rights said the toll had risen from an initial tally of 12 in the attacks on the town of Tal Tamr in Syria's Hasakeh province.
Observatory director Rami Abdel Rahman said one of the bombs detonated next to a post manned by Kurdish security forces and that members of the force were believed to have been killed, though he did not have a toll for them.
Another of the blasts was in front of a hospital, Abdel Rahman said, adding that four women and a doctor were killed.
He said dozens of people had been injured in the blasts and warned that the toll could rise further.
Tal Tamr, in Hasakeh's Khabur region, is controlled by Kurdish forces and has been targeted in the past by the Islamic State group.
In February, IS overran much of the Khabur region and kidnapped at least 220 Assyrian Christians during the offensive.
But Kurdish fighters from the People's Protection Units (YPG) subsequently recaptured the area, and dozens of the ISIS-held hostages have been released in recent months.
On Wednesday, some 25 Assyrian hostages, including two children, were freed by ISIS, according to the Assyrian Human Rights Network.