An offensive by Turkey and its Syrian allies is nearing a camp for displaced people in northern Syria holding thousands of members of "Islamic State families", some of whom have managed to escape after the site was shelled, Kurdish officials said.

The shelling of the camp at Ain Issa north of Raqqa represented "support for the revival of the Daesh organisation once again", the Kurdish-led administration for northern and eastern Syria said, referring to Islamic State militants.