A car bomb went off near a busy marketplace and mosque in Azaz, a rebel-held city in northwestern Syria, killing 17 people and injuring more than 20, a war monitor―Syrian Observatory for Human Rights―reported on Sunday.
Among the victims were four children and people who were shopping for gifts ahead of the upcoming Eid al-Fitr holiday, which marks the end of the holy month of Ramadan in the Islamic calendar, the Syrian Observatory for Human Rights said.
The blast was the largest in months to target Azaz, near the Turkish border.
The explosion happened around iftar, the time people broke their Ramadan fast, and were leaving the mosque after the evening prayers.
The victims and their relatives were taken to the local hospital, where officials said the emergency rooms were full.
No group has claimed responsibility for the attack so far.
The town, which was once controlled by rival Kurdish fighters opposed to Turkey, has been hit by similar attacks in the past.
The bombing comes a day after an explosion killed 10 people and injured 20 in the northeastern city of Raqa.
Islamic State militants have repeatedly carried out attacks across northern Syria in areas held by insurgents and by Kurdish-led forces.
(With inputs from agencies)