Rival Kurdish groups clashed in Iraq's northwestern Sinjar region on Friday, two Kurdish security sources said, causing deaths on both sides.
The fighting erupted when so-called "Peshmerga Rojava" forces deployed towards the border with Syria, encroaching on territory controlled and claimed by a local affiliate of the Kurdistan Workers' Party (PKK) operating in Iraq.
The unrest highlights the risk of conflict and turf wars between the multiple forces arrayed against Daesh, many of which lean on regional patrons for political support or arms.
"There are martyrs and wounded on both sides," one security source said.
The Peshmerga Rojava force is made up of Kurds from Syria and was formed and trained in Iraq with the backing of Masoud Barzani, the leader of the Kurdistan Democratic Party and the president of Iraq's autonomous Kurdistan Regional Government (KRG), who enjoys good relations with Turkey.
Turkey is at war with the PKK, which established a foothold in Sinjar after aiding Iraq's Yazidi population when Daesh overran the area in the summer of 2014, and set up a local franchise known as the YBS.
In a statement released today, the YBS said the fighting began when the Peshmerga Rojava tried to seize its positions in the town of Khanasor. The YBS accused Turkey of instigating the violence.
"It is a totally provocative initiative," the YBS said.
Turkey's Foreign Minister Mevlut Cavusoglu said earlier today that the PKK posed "a threat against the legitimate regional government in Northern Iraq and they are used by some countries against the current administration there."
"It's our duty to destroy these terrorist organisations wherever they are," the minister told reporters in Ankara.