Four Turkish soldiers were killed on Sunday in the eastern province of Hakkari after a device planted in a military operating area exploded, security sources said, according to Reuters.
An officer was among the dead and searches were underway for further devices, they added.
Turkey's military is engaged in a conflict in southeast Turkey with separatist Kurdistan Workers' Party (PKK) militants.
Some 40,000 people have been killed in fighting between the PKK and the military since 1984, when the PKK took up arms with the aim of establishing an ethnic homeland in southeast Turkey.
Turkey's government is currently working on a "Kurdish initiative" aimed at addressing decades-old Kurdish complaints of discrimination, which it hopes will erode support for the PKK.