Three PKK militants were also killed.
The militants attacked a post near the town of Pervari in Siirt. Authorities were not immediately available for comment.
The PKK planted mines in the area to prevent or slow down army reinforcements, and also were firing on helicopters taking troops to the area, the Hurriyet newspaper said on its website, citing unidentified local sources.
Attacks in Diyarbakır
On Saturday night, the PKK also attacked the local police headquarters and another army post in the town of Hani in Diyarbakir province. At least two policemen were wounded.
The PKK is listed as a terrorist organization by Turkey, the United States and the European Union.