Damascus, May 30 (IANS): Militant groups killed as many as 31 Syrian forces in the northwestern town of Ariha, which fell in the hands of the militants on Thursday, a monitor group said on Friday.

The so-called al-Fath Army, a coalition of several extremist groups mainly the Al Qaeda-linked Nusra Front, executed 13 government forces, including one Hezbollah fighter, in Ariha in the southern countryside of the northwestern province of Idlib, said the Syrian Observatory for Human Rights.

The London-based watchdog group said another 18 Syrian soldiers were killed when the al-Fath militants targeted their convoys during the military withdrawal from Ariha toward government-controlled positions in Idlib, Xinhua reported.

A day earlier, the al-Fath army overran the town of Ariha, marking the latest defeat for the Syrian troops in the key province of Idlib near the Turkish borders.

Ariha was one of the few remaining towns in the hands of the Syrian army in Idlib, where the provincial capital and much of the towns fell in the hands of that Al Qaeda-affiliated groups over the past two months.

The Observatory said tens of military vehicles withdrew from the town toward the areas of Arom al-Jous and Mhambel between Ariha and the city of Jisr al-Shughour, which was the latest to fall last month.

The offensive signifies the militants' resolve to expand their control to the entire province of Idlib, just a couple of years after the Islamic State (IS) group captured the northern city of al-Raqqa.