The Kurdistan Workers' Party (PKK) militants have attacked Turkish security forces in the southeastern province of Hakkari, killing five soldiers.
Security sources said Friday that the militants attacked the troops on the road near Cukurca district while they were conducting a security check.
Eight other troops were also injured in the assault, the sources added.
No further details are available yet.
Ankara has been engaged in a large-scale campaign against the PKK in its southeastern border region in the past few months. The Turkish military has also been conducting offensives against the positions of the group in northern Iraq.
The operations began in the wake of a deadly July 2015 bombing in the southern Turkish town of Suruc. More than 30 people died in the attack, which the Turkish government blamed on the Daesh Takfiri terrorist group.
After the bombing, the PKK militants, who accuse the government in Ankara of supporting Daesh, engaged in a series of attacks against Turkish police and security forces, in turn prompting the Turkish military operations.