26 September 1943, by an open condemnation by the German Bishops which, from every German pulpit, denounced the killing of "innocent and defenceless mentally handicapped, incurably infirm and fatally wounded, innocent hostages, and disarmed prisoners of war and criminal offenders, people of a foreign race or descent". However, the deportation of Polish and Dutch priests by the occupying Nazis by 1942—after Polish resistance acts and the Dutch Catholic bishops' conference's official condemnation of anti-Semitic persecutions and deportations of Jews by the Nazis—also terrified ethnic German clergy in Germany itself, some of whom would come to share the same fate because of their resistance against the Nazi government in racial and social aspects, among them Fr. Bernhard Lichtenberg. Himmler's 1941 Aktion Klostersturm (Operation Attack-the-Monastery) had also helped to spread fear among regime-critical Catholic clergy. Protestant resistance to the Nazi regime Following the Nazi takeover, Hitler attempted the subjugation of the Protestant churches under a single Reich Church. He divided the Lutheran Church (Germany's main Protestant denomination) and instigated a brutal persecution of Jehovah's Witnesses, who refused military service and allegiance to Hitlerism. Pastor Martin Niemöller responded with the Pastors Emergency League which re-affirmed the Bible. The movement grew into the Confessing Church, from which some clergymen opposed the Nazi regime. By 1934, the Confessing Church had promulgated the Theological Declaration of Barmen and declared itself the legitimate Protestant Church of Germany. In response to the regime's attempt to establish a state church, in March 1935, the Confessing Church Synod announced: In May 1936, the Confessing Church sent Hitler a memorandum courteously objecting to the "anti-Christian" tendencies of his regime, condemning anti-Semitism and asking for an end to interference in church affairs. Paul Berben wrote, "A Church envoy was sent to Hitler to protest against the religious persecutions, the concentration camps, and the activities of the Gestapo, and to demand freedom of speech, particularly in the press." The Nazi Minister of the Interior, Wilhelm Frick responded harshly. Hundreds of pastors were arrested; Dr Weissler, a signatory to the memorandum, was killed at Sachsenhausen concentration camp and the funds of the church were confiscated and collections forbidden. Church resistance stiffened and by early 1937, Hitler had abandoned his hope of uniting the Protestant churches. The Confessing Church was banned on 1 July 1937. Niemöller was arrested by the Gestapo, and sent to the concentration camps. He remained mainly at Dachau until the fall