Isis tells Raqqa residents to evacuate over fears nearby dam will collapse

Islamic State says US-led airstrikes have weakened Tabqa dam on Euphrates river, 25 miles from its self-styled capital in Syria

Islamic State has ordered residents of Raqqa to evacuate after reports that a nearby dam weakened by US-led coalition airstrikes could collapse, activists have reported.

Isis said air attacks had weakened the Tabqa dam on the Euphrates river, 25 miles (40km) west of Raqqa, and the water level behind it was rising. The militant group captured the city from Syrian rebels in 2014 and it is the capital of Isis's self-styled caliphate.