In 1938, a campaign was started by local "Selbstschutz" in the Czechoslovakian Sudetenland in order to subjugate the local Czechs prior to the Munich Conference. During the Invasion of Poland of 1939, a number of similar units conducted sabotage actions directed by the emissaries trained in Nazi Germany. These groups were officially merged into one organization, the ethnic German "Volksdeutscher Selbstschutz" (Self-Defense Force) of more than 100,000 men. They took part in fighting the Poles as the Fifth Column, but also served as auxiliary forces of the Gestapo, "SS" and SD during the early stages of the occupation of Poland, and helped the Nazi administration in the newly formed "Reichsgau Danzig-West Prussia" and "Reichsgau Wartheland". They served as local controllers, informers, and members of execution squads particularly active in the wave of mass murders of Polish intelligentsia during Operation Tannenberg and other more local and vengeful atrocities. The killings of Poles and Jews ascribed specifically to members of "Volksdeutsche Selbstschutz" is estimated at the minimum of 10,000 men, women and children. The force was disbanded in winter 1939/40 and the majority of its members joined the German "SS" or Gestapo by the spring of the following year.