At least eight Turkish soldiers were killed and 16 others injured in an ambush by Kurdish rebels on Tuesday, local officials said.
Ten rebels from the Kurdistan Workers' Party (PKK) were also killed in the fighting, which took place in Hakkari province, which borders northern Iraq, the governor's office in Hakkari said in a statement.
The PKK, designated a terrorist organisation by Turkey, the EU and the United States, has been fighting for autonomy in southeastern Turkey. Tens of thousands of people have died since the group took up arms in 1984.
The military are pursuing the insurgents.
There has been an increase in fighting between the PKK and the Turkish troops over the past year.
Three people were killed and 15 more injured in a bomb blast in the Turkish capital, Ankara, in September last year, which some blamed on the PKK.
Kurds make up around 20 percent of Turkey's 75-million population.