Six other auxiliaries were wounded in the ambush in the province of Bingol on Monday.
Police auxiliaries, known as "village guardians", have the task of protecting villages.
The sources said intensive military operations were in progress in the area.
In a separate incident, a bomb exploded early on Monday at a police station in a predominantly Kurdish region in the far east of Turkey, but there were no casualties, the Anatolia agency reported.
It was detonated by remote control and blew out windows and damaged a vehicle and a generator when it exploded in the courtyard of the station in the town of Hakkari, according to a senior local official cited by the agency.
Bomb-disposal experts blew up a second device found at the police station in a controlled explosion.
Clashes between Kurdish rebels and government forces died down after a unilateral declaration of truce by the rebels, formerly called the PKK or Kurdistan Workers Party in 1999.
But they resumed after an end to the truce was announced on 1 June and renamed their movement Kongra-Gel.
The PKK rebellion and its repression by the Turkish authorities are estimated to have cost 37,000 lives between 1984 and 1999.