A suicide bomber driving a fuel tank blew himself up on Monday at a checkpoint run by Islamist group Ahrar al-Sham in Syria's northern city of Aleppo killing at least 23 people, a monitoring group said.
The Syrian Observatory for Human Rights also said that four of the group's commanders and four civilians are believed to be among those killed.
It said that the attack in the city's Sukari neighborhood destroyed three nearby buildings and wounded dozens of people while many are believed to be stuck under rubble. Ahrar al-Sham officials were not immediately available for comment.