The organization was active in the ghettos of occupied Poland, in the General Government, and in Silesia. It served as a basis for organized resistance against the Germans. It also published underground newspapers.
Members of the organization took part in the Warsaw Ghetto Uprising and the Białystok Ghetto Uprising, after being incorporated into the structures of the Jewish Fighting Organization. In Białystok the bloc function under the name "Anti-Fascist Combat Bloc". Before the uprisings, the Bloc organized escapes from the ghettos and accumulated arms.