A statement by the military said the soldiers were killed during ongoing security operations in the mountainous Semdinli district of Hakkari province near the Iraqi border on Monday, adding that another soldier was also wounded.
The attack came a day after the Turkish General Staff announced that a soldier had been killed and two others injured when a hand grenade was detonated by accident in northern Iraq.
The wounded soldiers were reported to have been taken to hospital but they are not in critical condition.
PKK militants regularly clash with Turkish forces in the Kurdish-dominated southeast of Turkey attached to northern Iraq.
Turkey, along with the European Union and the United States, has declared the PKK a terrorist group and has banned it. The militant group has been seeking an autonomous Kurdish region since 1984.
A shaky ceasefire between the PKK and the Turkish government collapsed in July 2015. Attacks on Turkish security forces have soared ever since.
Over the past few months, Turkish ground and air forces have been carrying out operations against the PKK positions in the country as well as in northern Iraq and neighboring Syria.
More than 40,000 people have been killed during the three-decade conflict between Turkey and the autonomy-seeking militant group.