A spokesman for U.S.-backed forces fighting the Islamic State group in Syria says his fighters are in control of an encampment in the village of Baghouz where IS militants have been besieged for months.

Mustafa Bali, of the Kurdish-led force known as the Syrian Democratic Forces, says clashes however are continuing elsewhere in the village in eastern Syria as IS militants continue to fight back.

Bali says on Twitter on Tuesday that controlling the encampment in Baghouz marks "significant progress" in the fight but that it's "not a victory announcement."

The area held by IS in Baghouz is the last pocket of territory in Syria controlled by the extremist group, which once held a vast area of Syria and Iraq, calling it an Islamic "caliphate."