NKVD

The People's Commissariat for Internal Affairs (Народный комиссариат внутренних дел, Narodnyy Komissariat Vnutrennikh Del), abbreviated NKVD (НКВД listen) was the public and secret police organization of the Soviet Union that directly executed the rule of power of the All Union Communist Party, including political repression, during the era of Joseph Stalin.

The NKVD contained the regular, public police force of the USSR (including traffic police, firefighting, border guards and archives) but is better known for the activities of the Gulag and the Main Directorate for State Security (GUGB), which eventually became the Committee for State Security (KGB). It conducted mass extrajudicial executions, ran the Gulag system of forced labor camps, suppressed underground resistance, conducted mass deportations of entire nationalities and Kulaks to unpopulated regions of the country, guarded state borders, conducted espionage and political assassinations abroad, was responsible for influencing foreign governments, and enforced Stalinist policy within communist movements in other countries.

Read more about NKVD:  History and Structure, NKVD Activities