The OZNA (Department of National Security) issued precise instructions on dealing with prisoners of war. An instruction issued on 6 May 1945 by the OZNA stipulates that prisoners are to be "liquidated on the spot":  Several thousand Slovene Home Guard POWs were taken by trains from the Austrian border at Dravograd to Maribor and from there to the town of Celje. From the town's railway station they were sent through Celje by foot towards the nearby Teharje camp, a prison camp that was administered by the OZNA. During the trip the prisoners were beaten and those that lagged behind were shot. There were also civilians in the columns. Their valuables were taken from them upon arrival at the camp. German civilians from the Kočevje region (Gottscheers) were also brought to Teharje. The Home Guard POWs were separated into three groups: the first group consisted of minors, the second consisted of those that were members of the Home Guard for less than five months, and the third group included others. However, there were exceptions of this rule. The third group had the harshest treatment at the camp and were often without water and food. Around 7,000 to 8,000 people passed through the Teharje camp. Prisoners from the third group were first set for liquidation. Their hands were tied in pair with another inmate and were meant to be transported by trucks to nearby execution sites. The OZNA engaged drivers from across the country to carry out the transports. The drivers were not informed about the details of the action. In late May and June 1945, when the Yugoslav army started emptying its prison camps in Slovenia, prisoners from the Teharje camp and the Stari Pisker prison were brought by trucks at night to the abandoned Barbara Pit mine in Huda Jama. Slovene Home Guard POWs that were singled out in Slovenj Gradec, Velenje, Kranj and Celje were the first ones to arrive on the last week of May. NDH troops were brought on foot. Once arrived, groups of 5–6 prisoners with hands tied with wire were stripped, ordered to kneel above a mine shaft and shot in the head, or were hit with a mine hammer or a pickaxe. In some cases, groups of 20–30 prisoners were tossed into a mine shaft, followed with hand grenades to finish off the victims. A number of prisoners were thrown in alive. Once the shafts were filled with corpses, the remaining prisoners were sent in the direction of Zagorje in northwest Croatia where they were killed, while the bodies were covered with lime to speed up decomposition.