Six Turkish soldiers have been killed in a rocket attack on a navy base in the southern city of Iskenderun, local media has reported.
It was not immediately clear who was behind the attack, but state media put the blame on members of the Kurdistan Workers' Party (PKK) who are fighting for autonomy in the region.
Soldiers at the base say they fired at the attackers, but it was unclear whether any of them were injured.
Seven other soldiers were wounded in Monday's attack, which targeted a military vehicle that was carrying troops for the changing of the guard.
PKK fighters have stepped up attacks on Turkish army posts in the southeast in recent weeks, with warmer weather allowing them to leave their mountain hideouts.
However, the group rarely attacks naval targets.
The incident comes one day after Abdullah Ocalan, the jailed leader of the PKK, reportedly decided to abandon the group's efforts to reconcile with the Turkish government.
Six people were killed at the weekend amid continuing violence in the southeast.
Thousands of Turkish soldiers are currently engaged in large-scale manoeuvres against the PKK in the area, with operations taking place in the provinces of Hakkari, Siirt, Tunceli, Diyarbakir and Bingol.