At least 18 people have been killed in a car bomb blast in Idlib, Syria's largest rebel-held city, activists and a war monitoring group said.
The Britain-based Syrian Observatory for Human Rights said the car bomb was detonated on Sunday evening.
Photos and video from the activist-run Thiqa News Agency and Baladi News Agency showed heavy damage along what appears to be a major avenue in the city, with several buildings damaged and vehicles overturned.
Ambulances and the fire brigade are seen arriving at the scene.
No group immediately claimed responsibility for the bombing.
The city and Idlib province are controlled by several rebel factions and insurgents vying for dominance, the most powerful being an al Qaida-linked group.
The bombing came after Syrian television said the country's military had recaptured Sinjar, a strategically important town in Idlib province, in its latest advance into rebel-held territory this year.
The state-affiliated Al-Ikhbariya TV said government forces took Sinjar on Sunday.
The Syrian Observatory for Human Rights said the gain "opens the road" for government troops to march on the rebel-held Abu Zuhour air base about 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 UN said more than 2.5 million people are currently living in Idlib, including more than one million displaced by fighting from other parts of Syria.