The clashes with the Kurdistan Workers' Party (PKK) in the Pulumur region started on Thursday evening and were still ongoing Friday, the sources said.

The PKK, listed as a terrorist group by Turkey and much of the international community, took up arms in 1984, sparking a conflict that has claimed some 45,000 lives.

In February, the rebels had threatened to end a unilateral truce, declared in August last year, while saying they would defend themselves "more effectively" against military operations.