At least 10 members of Syria's al-Qaeda affiliate, al-Nusra Front, have been killed in a blast at a mosque in north-western Idlib province, activists say.
The UK-based Syrian Observatory for Human Rights said that dozens more were injured in the city of Ariha.
People had been gathering at the mosque to break their Ramadan fast when there was an explosion, the monitoring group said.
The cause of the blast on Friday is not yet known.
An unnamed senior non-Syrian member of al-Nusra was reportedly killed in the explosion at Salem mosque, according to the Observatory.