Amir Shuja Pasha, a prominent Islamist from the area, was reportedly among the victims. He had reportedly attended the Al-Nour Mosque in the town, and his family had prayed at the mosque three days beforehand, as the holy month of Ramadan was still underway.

The attack was the latest in a series of attacks across the country targeting worshippers of other faith groups since November 20, when a car rammed into a crowd in Nice, killing 86, mainly foreigners.

“One of the most violent attacks in Syria’s second largest city in three months, which also injured several people, was perpetrated by an Islamic organization against a mosque, in response to the killing of two Muslim clerics in Syria,” the AFP quoted Ali Shamkhani, leader of the Free Syrian Army’s armed wing Liwa’ al-Mujahideen and the prime minister of the embattled rebel-held Idlib province, as saying.

He said the attack was “an attack against religious sentiment that has been propagated by al-Qaeda and its affiliates as well as ISIS and Jabhat al-Nusra,” an increasingly powerful rebel group.

There have already been several attacks in Idlib this month, including an attack at a mosque where ISIS was once headquartered and a mosque in the town of Sheikh Miskine in which a woman reportedly died among worshippers.

Other attacks included twin car bombings in Aleppo earlier this month and a bombing of a mosque in southern Damascus on June 2.

The last time the government’s security forces opened fire to repress religious and ethnic minorities, it was during the months of 2011-2012, when they killed between 75 and 160 people when rebels torched at least 300 buildings and an army base in SANA city.

The violence against the minority Alawites has taken place in more extreme attacks against Muslim communities in recent years. In February this year, a mosque in Idlib was bombed, killing at least 28.

The violence has also reached its worst in the northwestern rebel-held part of the country, where a Syrian military checkpoint was blown up by an Islamic State suicide bomber on June 25.

The group claimed responsibility for the attack.