Forty-eight PKK militants were killed during the military operation, while three Turkish soldiers were killed and three wounded, Defense Minister Hulusi Akar said in a statement. Twelve of the kidnapped Turks had been shot in the head and one in the shoulder, he said.

Turkey launched the military operation against the PKK in northern Iraq’s Gara region on Feb. 10 to secure its border and find citizens who had been kidnapped previously, he said.

The governor of Malatya province in southeast Turkey named six soldiers and two police officers, kidnapped in separate incidents more than five years ago, as being among those killed in the cave. Three of the dead have yet to be identified.

One senior security source told Reuters that Turkish intelligence personnel were among the dead.

A statement on a PKK website said some prisoners it was holding, including Turkish intelligence, police and military personnel, had died during clashes in the area. The group denied it had ever hurt prisoners.

In 2017, Turkey’s foreign minister said Ankara was working to bring back citizens he said had been kidnapped by the PKK, after Turkish media reported two Turkish intelligence officers had been captured by the PKK in Iraq.

The PKK, designated a terrorist group by Turkey, the United States and European Union, launched its armed insurgency in mainly Kurdish southeast Turkey in 1984 and more than 40,000 people have been killed in the conflict.

In the last two years Turkey’s fight against the PKK has increasingly focused on northern Iraq, where the group has its stronghold in the Qandil mountains on the Iranian border.