Idlib Jabhat al-Nusra tank
Islamist Syrian rebel group Jabhat al-Nusra members pose on a tank in northern Idlib province.Reuters

The al-Qaeda-linked al-Nusra front has allegedly killed at least 20 Druze villagers in northwestern Syria.

The Syrian Observatory for Human Rights (SOHR), a London-based opposition group with a network of local sources, reported the mass killing took place in Qalb Lawzah in Idlib after an argument erupted between a Tunisian Nusra leader and villagers.

The Tunisian commander tried to seize a house belonging to a Druze man who he claimed was a soldier loyal to the Assad regime. That caused a reaction from the relatives of the owner who attempted to block the jihadist.

"The Nusra militant opened fire and killed a person from the village," the Observatory said. The crowd was able to pull the jihadist's gun and killed a militant from the rebel Islamist group.

"Al-Nusra called for reinforcements to take over the village and after that they opened fire with heavy machine fire, killing 20 people including a child and elderly people," it said.

Syrian state news agency Sana said at least 30 people were killed, but did not mention they were Druze and said the massacre was carried out by "Saudi and Turkish-backed groups".

Sources told the BBC that the Nusra commander accused the Druze of being "kuffar" infidels before ordering the killings.

Considered heretical by jihadists, the Druze faith is a reinterpretation of the three monotheistic religions (Islam, Hebraism and Christianity). There are about 1.5 million Druze believers in Syria, Lebanon and Israel.