Members of Turkey's security forces have been killed in clashes with Kurdish militants in the southeastern province of Sirnak.
Ten soldiers and policemen are reported to have been killed.
At least eight other members of the security services were injured in the clashes.
Fighting between the Turkish army and rebels from the outlawed Kurdistan Workers Party (PKK) has intensified in recent months.
More than 40,000 people have been killed in the conflict between the PKK and Turkish forces since the militants launched their insurgency 28 years ago.
The organisation aims to carve out a separate state in mainly Kurdish southeastern Turkey.
The PKK is listed as a terrorist organisation by Turkey, the United States and the European Union.