Three Turkish soldiers were killed on Friday after clashing with Kurdish militants in the southeastern province of Hakkari, military sources said.
The military launched an operation in the region, which borders Iraq, following the clashes, the sources said. The private Dogan news agency reported that several Kurdish militants had been "neutralized".
Turkey's southeast has been rocked by violence following the collapse of a 2-1/2-year ceasefire between the state and the outlawed Kurdistan Workers Party (PKK) in July last year. The PKK has repeatedly targeted security forces since.
Some 49 PKK militants were killed or captured in operations last week, the Interior Ministry said on Monday, adding that 269 people suspected of aiding and financing the militant group had been detained.
More than 40,000 people have been killed in the conflict since the autonomy-seeking PKK took up arms in 1984. It is considered a terrorist group by Turkey, the United States and the European Union.