At least 41 people were killed and several others injured in a car bomb blast at a security checkpoint in Syria’s al-Bab on Friday, Reuters reported. Officials said the attack targeting Turkey-backed Syrian rebels was perpetrated by the Islamic State group.

The suicide bomber detonated the explosive when he was at a crowded checkpoint supervised by Free Syrian Army rebels in the village of Sousian, northwest of al-Bab, Al Jazeera reported.

On Thursday, the rebels had succeeded in gaining control over the extremist group’s stronghold in al-Bab, along with two smaller neighbouring towns of Qabasin and al-Bezah.

The conflict in Syria has President Bashar al-Assad, backed by Russia, Iran and Shia militia fighting rebels backed by Turkey, United States of America and several gulf countries. Both factions are also simultaneously trying to oust the Islamic State group from the region.