The fighting erupted in the mountainous province of Tunceli where a military operation was under way against the separatist Kurdistan Workers' Party (PKK), resulting in two deaths Wednesday, the governor's office said in a statement carried by Anatolia news agency.

Another five militants were killed Thursday as the operation, backed by air power, continued in the area, security sources said.

The PKK, listed as a terrorist group by Ankara and much of the international community, took up arms for self-rule in the Kurdish-majority southeast in 1984, sparking a conflict that has claimed some 45,000 lives.

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