Two bomb blasts hit the northeastern Syrian city of Qamishli near the Turkish border on Wednesday, causing at least 44 deaths.
The British-based Syrian Observatory for Human Rights said at least one of the explosions hit near a building belonging to the Kurdish administration that controls most of Hasaka province, in which Qamishli is located.
State TV said one blast was from a car bomb and the other from a bomb on a motorbike.
One explosion was so powerful it shattered the windows of shops in the Turkish town of Nusaybin, directly across the border. Two people were slightly hurt in Nusaybin, a witness said.
ISIS claimed responsibility for the attack, saying they had targeted Kurdish security forces.
(With inputs from Reuters.)