The Iraqi arm of Isis has reportedly executed dozens of Kurdish members for refusing to take part in militant attacks in Kurdish regions in Syria.
According to sources, cited by the Kurdish daily Rudaw, Isis has slaughtered at least 40 men in Tal Hamis, the largest Kurdish city in Syria.
The city has witnessed some of the bloodiest violence since the beginning of the crisis, created by the Sunni insurgent group capturing vast swathes of Iraq and Syria.
News of the latest bout of mass killings is emerging when Turkey has started shutting down some of its border frontiers with Syria following the influx of about 100,000 Kurdish refugees in just two days.
Turkey is struggling to find resources to accommodate the ever-swelling number of refugees.
On Sunday, clashes broke out between Turkish security forces and Kurds during demonstrations demanding that Ankara admit more Kurdish refugees.
While the police forces attempted to quell the protests with water cannon and tear gas, the rioters responded with rocks.