A soldier was also injured in the fighting between the army and rebels from the outlawed Kurdistan Workers' Party (PKK) near Hozat in Tunceli province, the sources said.

Army chief Yasar Buyukanit said last week that "large-scale" operations had been launched against the PKK with the arrival of spring, the time when the rebels step up attacks as snow melts in the mountains, facilitating their movement.

The latest clashes brings the PKK death toll to at least 40 since the beginning of the month. The clashes have also claimed the lives of 11 soldiers.

More than 37,000 people have been killed since 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 of Turkey in 1984.

Turkey says thousands of rebels have found refuge in neighbouring northern Iraq where they are able to obtain weapons and explosives for attacks on Turkish targets across the border.

On Thursday, Buyukanit publicly argued for a cross-border operation into the Kurdish-held enclave to hunt down the rebels.