Rebels from the Kurdistan Workers Party (PKK) on Wednesday first threw a grenade and then opened fire with rifles on the convoy which was returning from duty in a rural area of Bingol province, the military said.

One soldier died at the scene and three others were taken to Bingol hospital for treatment.
   
Troops backed by helicopters launched an operation in search of the guerrillas, who fled under cover of darkness into the surrounding mountainous region. 

The PKK launched a violent separatist campaign for an ethnic homeland in south-east Turkey in 1984.

More than 30,000 people have died in the conflict, which subsided after the 1999 capture of rebel leader Abdullah Ocalan.
   
There has been an upsurge in violence since the PKK declared an end to its unilateral, six-year ceasefire in June.