PKK terrorists revealed late Tuesday that they were ordered by high-ranking militants to execute the Turkish citizens they had been holding captive in a cave in northern Iraq.

"If an operation starts, if something breaks out, if reinforcements fail to arrive, we were told to kill the hostages. He (the PKK commander) ordered that we would kill the Turkish hostages, police officers, soldiers. He told us to do this," Osman Acer, a PKK terrorist who surrendered to the Turkish security forces said in testimony.

"Later, he returned and took some people with him; he went near the hostages. He went toward the Turkish soldiers, police officers, and he killed them. Clashes continued for several days," he added, referring to the PKK commander who executed the citizens.

"We saw the hostages lying dead on the floor, shot in their heads. I couldn’t bear the scene. I was also hearing the calls for surrender by the soldiers. I got outside to surrender to the soldiers," another PKK terrorist, named Doğan Geçgel, also revealed.

"I went toward the soldiers to surrender. The soldiers took me with them. The Gara commander, named Cuma Biliki, previously told the responsible person, named Sorej, 'If an operation is conducted here, none of the hostages should be left alive, not meet their families.' I heard him giving this order," he said.

"I heard him ordering to kill the hostages. I’ve heard this with my own ears," he concluded.

PKK terrorists recently executed 13 Turkish citizens in a cave in northern Iraq after abducting them and shooting most of them in the head.

The PKK managed to establish a foothold in Iraq, particularly in the Sinjar region in mid-2014 on the pretext of protecting the local Yazidi community from Daesh terrorists. Since then, the PKK has reportedly established a new command base in Sinjar to carry out logistical activities.

Turkey has long been stressing that it will not tolerate threats posed to its national security and has called on Iraqi officials to take the necessary steps to eliminate the terrorists. Ankara previously noted that if the expected steps were not taken, it would not shy away from targeting the group. Recently, Minister of National Defense Hulusi Akar expressed that Turkey was prepared to provide assistance to Iraq in clearing terrorists from the region. Iraq's Kurdistan Regional Government (KRG) has called the PKK's presence in Sinjar unacceptable and urged the militants to leave the area.

Turkey launched Operations Claw-Tiger and Claw-Eagle last June to ensure the safety of Turks and its national borders by eliminating terrorist threats. Operation Claw-Eagle 2 was launched last week.

In its more than 40-year terror campaign against Turkey, the PKK – listed as a terrorist organization by Turkey, the U.S. and the European Union – has been responsible for the deaths of 40,000 people, including children.