BEIRUT: Turkish forces and Syrian rebels expelled ISIS from the last areas of the Syrian-Turkish border under their control Sunday, the Syrian Observatory for Human Rights said.

"[ISIS] has lost its contact with the outside world after losing the remaining border villages," the Britain-based activists group said.

The Observatory said "rebels and Islamist factions backed by Turkish tanks and warplanes" had taken several villages on the border "after [ISIS] withdrew from them, ending [ISIS]'s presence... on the border."

The advance come after Turkey launched an operation dubbed Euphrates Shield on Aug. 24, saying it was targeting both ISIS but also Syrian Kurdish forces that have been key to driving the jihadists out of other parts of the Syrian-Turkish border.

The Kurdish YPG militia is a key partner of the U.S.-led coalition against ISIS, and has recaptured large swathes of territory in Syria from the extremist group.

But Ankara considers the YPG a "terrorist" group and has been alarmed by its expansion along the border, fearing the creation of a contiguous, semi-autonomous Kurdish region in northern Syria.

The loss of the Turkish border will deprive ISIS of a key transit point for recruits and supplies, though the group continues to hold territory in both Syria and Iraq.