SYRIA’S ARMY cut off invading Turkish troops’ route to the Isis stronghold of Raqqa yesterday amid reported clashes between Ankara-backed insurgents and government soldiers.

Syrian troops broke through Isis lines south-east of al-Bab and captured a string of villages up to the Kurdish YPG militia’s lines around Manbij, west of the Euphrates river.

The swift advance left a small pocket of some seven villages under nominal Isis control — which the Turkish army and its Free Syrian Army (FSA) allies moved to take over immediately.

That followed Sunday’s capture by the army of Tadef, just south of al-Bab which the Turkish-led Operation Euphrates Shield forces took late last week after Isis extremists retreated.

Reports came overnight of FSA militants attempting to seize Tadef from the army — a dangerous escalation between allies of Nato member Turkey and Russia.

The Middle East Eye website quoted a Syrian military source saying that Turkish-backed rebels had “targeted our forces in Tadef with artillery and machine-guns.”

The attack showed the invaders’ “main aim is not fighting Isis but realising other goals, including an attempt to obstruct the Syrian army’s operation confronting Isis,” the source added.

The FSA alleged that the army had attacked first in a bid to retake al-Bab.

A source said Turkish forces were not involved in the clashes.

Turkish President Recep Tayyip Erdogan has repeatedly vowed that his forces will not stop at the town in the northern province of Aleppo but continue to the central Syrian city of Raqqa.

On Friday, Turkey’s Chief of General Staff Hulusi Akar said his country’s military goals had been achieved with the capture of al-Bab.

The pro-YPG Hawar news agency reported yesterday that Turkey was moving more troops into the the Syrian border town of Azaz in preparation for a new assault on Kurdish-held areas.

And Mr Erdogan’s chief adviser Ilnur Cevik said the next step was to drive the YPG from Manbij — potentially opening a new road to Raqqa.

“Turkey will do everything right now to restore the Arab population in Manbij, clear it of Kurdish militants,” he vowed.

“Turkey will stop its operations in Syria after Manbij is taken.”

On Sunday, the YPG-dominated Syrian Democratic Forces militia alliance said that it was close to cutting the main road north of the Euphrates from Raqqa to Deir Ezzor, an eastern city of 200,000 people where the army has held out against a three-year Isis siege.