Extermination battalions or destruction battalions, [nb 1] colloquially istrebitels (истребители, "exterminators", "destroyers") abbreviated: istrebki (Russian), strybki (Ukrainian),[1][2] stribai (Lithuanian), were paramilitary units under the control of NKVD in the western Soviet Union, which performed tasks of internal security on the Eastern Front and after it.

[4] Vladimir Tributs the Commander-in-Chief of the Baltic Fleet of the Soviet Union issued an order on 24 June 1941 warning of the paralysing actions of enemy paratrooper squads aided by the "capitalist-kulak" portions of the populations, which allegedly had a large number of weapons that had not been turned in.

The struggle against saboteurs was the responsibility of the border guard units subordinate to the NKVD (People's Commissariat of Internal Affairs of the Soviet Union).

Everybody, who directly or indirectly helps the enemy, must be found out and exterminated.The extermination battalions were formally voluntary while actually a number of troops were forcibly recruited.

[9][10] During July–August 1941 in the Byelorussian SSR, chiefly in Vitebsk, Homel, Polesia, Mohylew oblasts, 78 such battalions were created, comprising more than 13,000 personnel.

[11][12] The battalions were also formed in the newly annexed territories of Karelo-Finland, Estonia, Latvia, Lithuania, East Poland, Galicia, and Bessarabia.

[15][16][17][18] The fight against Anti-Soviet partisans and the implementation of the scorched earth tactics were accompanied by terror against the civilian population, which was treated as supporters or shelterers of Forest Brothers.

[19][20] Thousands of people including a large proportion of women and children were killed, while dozens of villages, schools and public buildings were burned to the ground.

The low toll of human deaths in comparison with the number of burned farms is due to the Erna long-range reconnaissance group breaking the Red Army blockade on the area, allowing many civilians to escape.

This included terrorising the actual or potential supporters of Forest Brothers among the civilian population, participation in active combat, organisation of ambush and secret guard posts, reconnaissance and search patrols.

A typical task was to force the farmers to fulfil public forestry, peat extraction and road construction obligations.

[25] The extermination battalions were great in size, but they never became the efficient and active armed force which they were expected to become in order to rapidly eradicate the Forest Brothers.