Kurdistan Workers Party (PKK) militants launched a car bomb attack on a military installation in southeast Turkey overnight, killing one soldier, while Turkey's army destroyed PKK targets in air strikes and killed more than 20 militants.
The violence showed no let-up in a conflict that has killed thousands of militants and hundreds of security force members and civilians since a 2-1/2 year ceasefire collapsed last July, shattering a peace process.
The armed forces said the PKK was behind the car bomb attack at 00:50 am (2150 GMT) on a gendarmerie base in the Derik district of Mardin province, near the Syrian border.
Five people were wounded in the blast, four of them soldiers, it said.
The military also carried out air strikes on Tuesday in the southeast provinces of Sirnak and Hakkari, destroying PKK gun positions, shelters and caves, it said in a separate statement.
On Tuesday the army killed 13 militants in the Cukurca area by the Iraqi border, Sirnak and Nusaybin, it said.
In Diyarbakir province, the armed forces have killed more than 10 PKK fighters since Monday, the local governor's office said in a statement.
The PKK, designated a terrorist group by Turkey and its Western allies, began a separatist insurgency in 1984 and more than 40,000 people have been killed in the conflict.