Five Turkish soldiers were killed and seven injured in an attack Wednesday near a border post along the country's south-eastern border with Iraq, the state-run Anadolu news agency reported.
The attack included an explosive device, gunfire and rocket fire from the Iraqi side, the private Dogan news agency said, citing the military.
The Kurdistan Workers' party (PKK), an armed group, has bases and operations in northern Iraq.
The incident - also reported by the pro-Kurdish Firat news agency, which said eight soldiers were killed - took place in volatile Sirnak province, which has seen heavy fighting during the past year, leaving large swaths of the area devastated.
The army repeatedly imposes strict curfews on residents of Sirnak and other provinces in mostly Kurdish south-eastern Turkey.
In Diyarbakir province's Kulp area, two soldiers were killed late on Tuesday by gunfire, both Firat and Anadolu reported.
A ceasefire between the state and the PKK collapsed in 2015, after holding for more than two years, when the state put peace talks on hold.
Since then, more than 600 members of the security forces have been killed, the government has confirmed. Meanwhile, some 670 militants are confirmed dead by the PKK, according to the International Crisis Group think tank.
Hundreds of civilians have also been killed in the fighting, while about half a million residents have been displaced.
The PKK and the state have been fighting for more than 30 years, leaving more than 40,000 people dead. The Kurdish minority has long complained of systemic discrimination. Many demand greater autonomy in the south-east.