The bodies of Necman Olmez and Ferhat Edis, both in their 30s, were found overnight Saturday in a precipice outside the town of Beytussebap after their abandoned car was spotted nearby.

They had been shot in the head and chest.

Security forces launched a search for the pair on Saturday after local residents told the Democratic Society Party, to which Olmez and Edis belonged, that they had seen unidentified people stop their car on a road outside town and lead them away, the security sources said.

An investigation is underway, but there is immediate word as to who the perpetrators might be.

Turkey's Kurdish-majority southeast has been the scene of a bloody conflict between the security forces and the outlawed Kurdistan Workers' Party (PKK), which took up arms for self-rule in the region in 1984.

The killings come as prosecutors step up efforts to shed light on allegations that a number of Kurds who went missing in the 1990s, at the height of the PKK insurgency, were victims of summary executions by security forces.