Three Turkish troops were killed on Thursday when Kurdistan Workers Party (PKK) militants opened fire on their convoy in the southeastern province of Sirnak.

Three Turkish troops were killed on Thursday when Kurdistan Workers Party (PKK) militants opened fire on their convoy in the southeastern province of Sirnak, the army said.

"As a result of an attack by the Separatist Terror Organization three of our brave personnel - one officer, one non-commissioned officer and one private - were killed," said the army in a statement, using its customary phrase for the PKK which it never refers to by name.

The army said that the military convoy was ambushed by PKK members as it was travelling along a road while carrying out a security operation in the Akcay district of Sirnak province, which borders both Syria and Iraq.

"Drones, helicopter gunships and commando units have been dispatched to the scene," it said, adding that one "terrorist" had been killed in the clashes and operations were continuing.

The killings are the latest in a spike in unrest as Turkey carries out a bombing campaign against targets of militants of the so-called 'Islamic State of Iraq and the Levant' (ISIL) takfiri group in Syria and PKK militants in northern Iraq.

The PKK has largely observed a ceasefire since 2013 but over the last week deadly attacks on the security forces blamed on the militants have occurred almost daily.