Kurdish forces in northern Syria say they have captured a key military base from Islamic State (IS) north of the militants’ self-declared capital of Raqqa, the BBC reports.

The Kurdish Popular Protection Units (YPG) were backed by US-led air strikes and other rebel groups.

It comes a week after Kurdish forces seized a Syrian border crossing with Turkey from the jihadists.

The move cut off a major supply route for IS.

A Kurdish forces spokesman said they had complete control of the Liwa (Brigade) 93 base, which is deep in IS-held territory.

Redur Xelil said the YPG was now on the outskirts of Ain Issa, a town only 50km (30 miles) north of Raqqa.

“They [IS] have been defeated,” he said.