The NKVD maintained a strict security system in the Wismut mines. NKVD/MVD troops guarded not only the mines, but the total Wismut zone of mines as well. having up to 15,000 troops there. These troops were under the command of the NKVD military head of Wismut. There were additional armed military units stationed in the uranium mining districts. Military and NKVD checkpoints were present at all approaches to this zone. The mines were surrounded by wooden fences and watch towers, and access to them was only through a guarded gate. There were also NKVD posts at district or town levels at the fourteen Wismut mines. A special NKVD group, commanded by a Major Malygin, was very important in its work at all the pits and plants of Wismut. He had the task of investigating all cases of espionage and diversion and reported directly to General Serov.Ulrich Merten, p.227
