The "Islamic State of Iraq and the Levant" (ISIL) is battling on several fronts in a swathe of territory in northern Syria, AFP reported Tuesday (June 7th).

Much of the fighting is centred around a main supply line snaking down from the Syrian-Turkish border to al-Raqa city.

The group is facing twin offensives -- from the Syrian Democratic Forces (SDF), a Kurdish-Arab alliance, and from pro-regime troops -- on either side of the town of Tabqa, a key transit town near al-Raqa.

To the north-west, ISIL is also nearly surrounded by an SDF offensive on the town of Manbij, another major hub along the route.

Since May 30th, the alliance has swept west towards Manbij, seizing at least 40 villages, with thousands of civilians fleeing the fighting.

Sherfan Darwish, who heads the SDF's Manbij offensive, told AFP the town is surrounded from three sides and "operations are progressing well".

The SDF stand just two kilometres to the south of the town, the Syrian Observatory for Human Rights monitoring group said.

"ISIL has begun allowing civilians to flee towards the west, whereas before they had banned anyone from leaving," Observatory chief Rami Abdel Rahman said.

He said some were in cars but many were carrying their belongings and walking along unpaved roads as ISIL fighters remained in the town.