Fighting broke out Friday in a mountainous area in the province of Hatay, which borders Syria, when soldiers on patrol came across militants from the Kurdistan Workers' Party (PKK), the general staff said on its website.

An operation was under way to catch the fleeing rebels, it added.

The PKK announced Wednesday that it had extended a truce in its separatist campaign until September 1 to help efforts to find a peaceful solution.

The extension was decided in anticipation of a "roadmap for a democratic solution" which jailed PKK leader Abdullah Ocalan is to propose in August, senior PKK commander Murat karayilan told the Europe-based Kurdish Fridat news agency.

Ankara has never formally recognised PKK's unilateral truces and the military has pursued operations against the rebels.

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