The soldiers lost their lives and six others sustained injuries in an exchange of fire with Kurdistan Workers' Party (PKK) militants in the southeastern Hakkâri province late on Friday, Turkish media reported.

In a separate incident in the southeastern Turkish province of Diyarbakir, a 40-year-old civilian was killed and a 29-year-old one injured early on Friday morning after the two were caught up in clashes between security forces and PKK militants.

Also on Friday, two police officers were injured in an ambush in the Nusaybin district of the southeastern Mardin province.

Two Turkish electricity engineers were also injured in an explosion of a landmine planted by the PKK in the southern province of Hatay.

Meanwhile, a top PKK figure warned on Friday that the Turkish government would pay "a heavy price" for its raids against the militants.

"We are experienced and we know very well what to do. They made a very big mistake by attacking us... They will pay a very heavy price for that," the PKK's northern Iraq-based leader Murat Karayilan was quoted by the pro-PKK Firat news agency as telling Kurdish Sterk TV.

Ankara launched airstrikes against purported ISIL targets in Syria as well as PKK positions in Iraq and Turkey after a deadly July 20 bomb attack by Daesh terrorists left 32 people dead in the southeastern Turkish town of Suruç, across the border from the northern Syrian town of Kobani.

But so far, the air raids have significantly concentrated on the Kurdish militants.

The PKK has been fighting for an autonomous Kurdish region in southeastern Turkey since the 1980s. A shaky ceasefire between Anakara and the PKK that had stood since 2013 was declared as null following the Turkish military campaign.