A suicide bomb blast has killed at least 16 people in the mostly Kurdish-controlled city of Hasaka in northeastern Syria, the monitoring group the Syrian Observatory for Human Rights said.
The attacker detonated his explosives at a bakery on Tuesday.
The British-based observatory said several other people were wounded and the death toll was likely to rise because of the number of serious injuries
There was no immediate claim of responsibility for the bombing.
Islamic State has targeted areas of Hasaka province in the past, including another city, Qamishli. But bomb attacks in Hasaka city itself have been rarer in recent months.
The Kurdish YPG militia, which controls most of Hasaka province, captured large areas of territory from Islamic State in northeastern Syria last year and is involved in a US-backed offensive against the jihadists further west near the Turkish border.