The clashes erupted in a mountain region in Tunceli province when troops came across Kurdistan Workers' Party (PKK) rebels, the officials said.

Fighting was continuing in the Ovacik region, they added.

Turkey has stepped up an offensive against the PKK since December with aerial raids on rebel hideouts in neighbouring northern Iraq.

Listed as a terrorist group by Turkey and much of the international community, the PKK has been fighting for self-rule in Turkey's southeast since 1984. The conflict has claimed more than 37,000 lives.

Ankara charges that more than 2,000 Kurdish rebels have found a safe haven in northern Iraq, where they are able to obtain weapons and explosives for attacks in Turkey.