A large car bombing in Syria's largest rebel-held city of Idlib killed at least 23 people on Sunday evening, activists reported.
The blast ignited fires, damaged buildings and overturned several cars along a wide avenue in the city, according to photos and video posted by the activist-run Thiqa News Agency and Baladi News Agencies. Ambulances and fire brigades were seen rushing to the scene.
Idlib is the capital of a province by the same name that is controlled by several rebel factions, including an al-Qaida-linked group, vying for dominance as government forces are pushing an offensive into the southeast corner of the region.
The bombing took place outside an office of an insurgent group called Ajnad al-Koukaz, according to the Britain-based Syrian Observatory for Human Rights and a local media activist who declined to be named out of fear of reprisals. The faction is made up of foreign fighters, mostly from the Caucuses and Russia, said the media activist. It is in alliance with an al-Qaida-linked faction that dominates the province, according to Observatory's chief Rami Abdurrahman.
It was not immediately clear who was behind the attack. There were no sounds of an airstrike, according to local activist Abdulghani Dabaan. Residents said they believed it was a car bomb.
Initial reports said 18 were killed but the death toll quickly rose to 23. Dozens were reported wounded, and at least 35 were brought to one of the city's hospitals, according to Mohammad al-Shaghal, a medical technician.
The explosion came hours after the Syrian military announced it had recaptured a strategically important town in eastern Idlib. The state-affiliated Al-Ikhbariya TV says government forces took Sinjar on Sunday.
The Observatory said the advance "opens the road" for the government troops to march on the rebel-held Abu Zuhour air base, about 19 kilometers (12 miles), to the north.
The military has assigned one of its top commanders to lead the offensive into Idlib, the last major stronghold for rebels in northern Syria. The U.N. says more than 2.5 million people are currently living in Idlib, including more than 1 million displaced by fighting from other parts the Syria.