The killings in the Jabal al-Zawiya region appeared to be part of the wider confrontation by an alliance of militants against al-Qaeda’s Islamic State in Iraq and the Levant (ISIL), across rebel-held territories of northern and eastern Syria.

The so-called Syrian Observatory for Human rights’ director Rami Abdulrahman said 34 were killed, most of them ISIL fighters, along with some others from an allied group called Jund al-Aqsa.

They were captured and separated from a group of militants and killed, he said.

It was not possible to verify the report independently due to reporting restrictions in Syria, where Syrian army has been fighting against a massive foreign-charged insurgency for nearly three years.

The latest infighting between militant groups erupted four days ago in the northern provinces of Aleppo and Idlib, fuelled by resentment against ISIL's radical agenda and a turf war near the Turkish border for strongholds which control supply routes into northern Syria.

The fighting has also spread to the eastern city of Raqqa, the only Syrian city fully occupied by extremist militants.

A recent British defense study showed that more than 100,000 militants, fragmented into 1,000 groups, are fighting in Syria against the government and people.

The extracts of the study by defense consultancy, IHS Jane's, were published on September 16.

IHS Jane's estimates that some 10,000 militants are fighting for groups affiliated with al-Qaeda such as al-Nusra Front, and the rest fight for different militant groups.

SHI/SHI