Turkey's NTV channel said the clash took place in the Sirnak province around 11:00 p.m. local time (20:00 GMT) on Wednesday.
"Gunmen, whose number was unknown, refused to surrender and opened fire," it said.
Media reports did not say whether Kurdish militants suffered any casualties.
The clash came a day after 15 Turkish warplanes bombed a group of PKK rebels inside northern Iraq, killing at least 20. The Turkish General Staff said they were planning to cross the border to launch attacks inside Turkey.
The Kurdistan Workers Party (PKK) has been fighting for an autonomous ethnic Kurd state in southeast Turkey for nearly 25 years. The conflict has so far claimed over 40,000 lives.
In late February, over 10,000 Turkish troops were involved in a ground operation in northern Iraq that targeted PKK bases. The eight-day operation saw the deaths of 27 Turkish military personnel and around 240 Kurdish militants, and led to widespread criticism from the West.
The General Staff acknowledged in a statement that the PKK had not been eliminated in the military incursion. Turkey also pledged to continue ground operations in Iraq.
In mid-March, the PKK said it was ready to discuss a ceasefire with Turkish authorities. Turkey has consistently refused to enter into a dialogue with the party, listed as a terrorist organization by the U.S., NATO and the European Union.