ISIL militants and competing insurgents have been fighting since the start of the year, killing over 3,000 people and undermining an uprising against President Bashar Assad.

On Friday, ISIL - which alienated many militants by seizing territory and killing rival commanders - finished withdrawing from the Idlib and Latakia provinces and moved its forces toward the eastern Raqqa province and the eastern outskirts of the northern city of Aleppo, activists said.

The Britain-based Syrian Observatory for Human Rights monitoring group said the withdrawal was overseen by the Nusra Front, al Qaeda's acknowledged branch in Syria, making the two provinces "completely free" of ISIL militants.

"There's been an uneasy calm on all sides" since the withdrawal of ISIL militants, one activist from Idlib province said.

The Observatory's director Rami Abdulrahman said ISIL had been weakened by clashes and defections in the areas it had withdrawn from, but still had some control over Raqqa province.

A video posted online on Friday showed two militants touring what they said were abandoned buildings that had been used by ISIL as a court and a prison in a town in the Jebel al-Akrad region.

The militant groups’ infighting has nevertheless further complicated a war that has killed over 140,000 people and forced millions to flee their homes. The war enters its fourth year this month.

NJF/NJF