Al-Qaeda affiliate Al-Nusra Front terrorist group seized a town and several villages in Syria’s Idlib province overnight, in another blow to Western-backed gunmen in the northwestern region.

Al-Qaeda affiliate Al-Nusra Front terrorist group seized a town and several villages in Syria's Idlib province overnight, in another blow to Western-backed gunmen in the northwestern region, a monitor said Sunday.

The opposition UK-based Syrian Observatory for Human Rights said Al-Nusra militants captured the town of Khan al-Subul after the withdrawal of the Hazm movement, another armed opposition group.

The Al-Qaeda affiliate also seized another five villages in the province held by armed groups, the Observatory said.

The advance comes a day after the Observatory reported Al-Nusra militiamen had seized the Idlib bastion of the so-called 'Syria Revolutionaries Front' (SRF), another Western-backed armed opposition group.

The Observatory said Saturday that Al-Nusra had captured Deir Sinbel and most of the other towns and villages in the Jabal al-Zawiya area of Idlib province.

The Observatory said some members of the SRF even deserted the group during the fighting and joined Al-Nusra's ranks.

The Hazm movement is among the armed groups that received supplies of US-made weapons, including TOW anti-tank missiles.

The Observatory said Al-Nusra seized weapons during its advance in Idlib province, but it was not immediately clear if US-made weapons were among those captured.

Since July, sporadic clashes have occurred between the Al-Qaeda affiliate and other rebel groups, particularly in Idlib province.