Three of the rebels were killed in clashes early in the day near the village of Cicekli in the eastern province of Tunceli, a region that has seen much fighting between government forces and rebels, local security forces said.

The other rebel was killed in fighting near the town of Cukurca in Hakkari province, which borders Iran and Iraq, the local governor's office said.

On Wednesday, security forces killed a separatist Kurdish rebel and a soldier died in a landmine explosion blamed on the militants.

Clashes between the rebels and security forces intensified after the army last month launched large-scale operations against the Kurdistan Workers' Party (PKK) in the east and southeast of the country.

More than 37,000 people have been killed since the PKK, listed as a terrorist group by Turkey and much of the international community, took up arms in 1984 for self-rule in the mainly Kurdish east and southeast of the country.