BEIRUT - A US-backed alliance of Syrian Kurdish and Arab fighters advanced against Islamic State in the northern Syrian province of Raqqa on Monday, a spokesman said, making further gains against the jihadists close to their stronghold.
The Syria Democratic Forces took several villages and farms close to the town of Ain Issa, some 50 km (30 miles) north of Raqqa city, Islamic State's de facto Syrian capital, spokesman Talal Selo said.
British-based monitoring group the Syrian Observatory for Human Rights said the alliance had taken six villages and farms, without elaborating. It said dozens of fighters from both sides had been killed in clashes in recent days.
The Syria Democratic Forces seized a dam from Islamic State last month, cutting one of its main supply routes across the Euphrates river.
The Kurdish YPG militia, part of the alliance, recaptured Ain Issa from Islamic State in July.
The alliance joins the YPG with various Arab groups including Jaysh al-Thuwwar (Army of Rebels) and the Arab tribal Jaysh al-Sanadeed, and an Assyrian Christian group.
Since it was formed in October, its fighters have opened several major offensives against Islamic State with the ultimate goal of capturing Raqqa.
The YPG has been the most effective partner on the ground for US-led air strikes against Islamic State.
Washington's strategy in Syria shifted in 2015 from trying to train thousands of fighters outside the country to supplying groups headed by US-vetted commanders.
US officials have said delivery of weapons since the alliance was set up would help the fighters push further south into Islamic State-held territory.