A total of 12 PKK terrorists have been killed in northern Iraq, security sources said Tuesday.

The terrorists were killed in northern Iraq's Hakurk region as they were reportedly preparing to carry out an attack on Turkish military bases, according to the sources, who spoke on condition of anonymity due to restrictions of speaking to the media.

The terrorists were found by military command drones in Yüksekova in the southeastern Hakkari province, according to the sources.

Founded in 1978, the PKK has waged a decades-long bloody campaign against Turkey.

The PKK, which is listed as a terrorist organization by Turkey, the U.S., and the EU, resumed its armed campaign in July 2015 after a brief reconciliation period.

Since that time, the PKK has been responsible for the deaths of some 1,200 security personnel and civilians, including women and children, while more than 4,000 security personnel and over 2,000 civilians have been injured.