Thousands of civilians have fled their homes in northern Syria as Kurdish forces carry out what appears to be a campaign of ethnic cleansing against Sunni Arabs.

A source from one of the largest humanitarian organisations working inside Syria told The Times that the Kurdish people’s protection units (YPG) — the west’s closest allies in the war against Islamic State — have been burning Arab villages in areas of northeastern Syria under their control.

These include settlements around Kobani, the border town that became a totem of Kurdish resistance after it held out against an Isis onslaught for four months late last year. More than 10,000 people are thought to have fled in the past six months as neighbours who had lived together for decades