A US-backed force of Syrian Kurdish and Arab fighters has taken control of an Islamic State-held airbase west of the jihadist group's stronghold of Raqqa.

Located near the River Euphrates about 40km (25 miles) west of Raqqa, the facility was seized by IS militants in August 2014, two months after they proclaimed the creation of a "caliphate". It was also the scene of one of the jihadists' worst atrocities - the mass killing of some 200 Syrian soldiers who were captured while trying to flee. 

The airbase's capture was part of a wider offensive aimed at also taking control of the Tabqa dam - the largest in Syria and a key source of electricity for the region. The coalition said the dam had been used by IS as a headquarters, as a prison for high-profile hostages, as a training location and to plot attacks outside Syria.

The Tabqa operation is part of a wider effort by the SDF to encircle and isolate Raqqa before launching an offensive to recapture the city. US officials estimate that there are 3,000 to 4,000 militants in the Raqqa area, alongside hundreds of thousands of civilians.

Read more: BBC News