A Turkish army sergeant was shot dead by a Kurdish militant near the Iraqi border Tuesday, the military said.
The soldier in civilian clothes "was shot in the head in front of a bank... by a member of the separatist terrorist organisation" in Semdinli in the mainly Kurdish southeast, the army said, using a term for the outlawed Kurdistan Workers' Party (PKK).
The soldier died of his injuries in hospital, it added.
Turkish media said a search operation was going on to find the killer.
Ankara has sparked Kurdish fury by expanded its cross-border bombing campaign against the Islamic State (IS) group in Syria last week to include PKK positions in northern Iraq, after deadly attacks inside Turkey blamed on the Kurdish separatists.
Turkey, which considers the PKK a terrorist organisation, launched peace negotiations with the group's jailed leader Abdullah Ocalan in late 2012, but the two sides have yet to reach an accord.
Turkish President Recep Tayyip Erdogan said Tuesday that peace talks cannot continue amid attacks on Turkey.