Four members of the Turkish security forces were killed in a firefight with Kurdish guerrillas in southeastern Turkey late on Wednesday, security officials said.
The clash broke out near the town of Pervari in Siirt province in the mainly Kurdish southeast, the officials said on condition of anonymity. A lieutenant and three village guards who work for the military were killed, they said.
Military operations that included helicopter gunships against the Kurdistan Workers Party (PKK) guerrillas were continuing.
The outlawed PKK has stepped up attacks on Turkish military targets after calling off its one-year truce on June 1, accusing Prime Minister Tayyip Erdogan's government of failing to find a political resolution to the 26-year conflict.
The PKK took up arms against Turkey in 1984 in a bid to carve out an independent Kurdish state, and more than 40,000 people, mainly Kurds, have died in the war.
Violence traditionally rises in the southeast, which borders Iraq where most of the PKK is based, in the spring and summer months as warmer weather allows the rebels and the army to move more easily through the region's mountainous terrain.