In the Soviet Union of World War II, NKVD labor columns (Russian: рабочие колонны НКВД) were militarized labor formations created from certain categories of population, both fully rightful Soviet citizens, as well as categories of limited civil rights.
Although persons of these categories were not permitted to serve in the Soviet Army, members of the labor columns were considered to be conscripted for military duty.
This started in 1941, when the NKVD (via Prikaz 35105) banned ethnic Germans from the Soviet military.
Most of them worked at "NKVD objects" (i.e., basically in the same conditions as in Gulag prison camps; the Germans were supposed to be housed in separate camps, but this was not always done), and in coal mining and petroleum industries, railroad construction, ammunition, general construction, and other industries.
In 1955, after the official visit of Chancellor of Germany Adenauer to the Soviet Union and the signing of a number of Soviet-German agreements, this status was abolished (the process of resettlement of Germans to Germany was started at this time as well).