There was no immediate official casualty toll but in a sign of the gravity of the situation Prime Minister Ahmet Davutoglu broke off a trip to Konya to watch a national football game and summoned an emergency security meeting in Ankara, the reports added.
NTV television said militants staged a mine attack on two military vehicles in a convoy in the Daglica district of Hakkari, a known PKK stronghold.
It added that Turkish F-4 and F-16 warplanes carried out strikes in retaliation against those suspected to have carried out the attack.
"A mine attack has been staged. There will be a very particular and decisive fight there. We are very sad," he told the A-Haber channel.
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"The weather conditions were unfavourable. A struggle was being waged under such conditions," he said, adding the attack happened during a "clean-up operation" against PKK militants.
The PKK has been staging daily attacks against the Turkish armed forces as the military presses an over month-long operation against the group in southeast Turkey and northern Iraq.