The remote-controlled blast took place while a military convoy was passing in the Şemdinli district, close to Turkey's border with Iraq.
PKK terrorists have carried out a string of attacks in southeast Turkey recently, killing more than 40 security personnel in the past month.
The Turkish military has launched retaliatory air raids on PKK targets in northern Iraq, its first strikes in the region in more than a year.
The PKK took up arms against the Turkish state in 1984 and more than 40,000 people have died in the conflict. It has bases in northern Iraq from which it crosses the border to attack Turkish targets.
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