Swiss citizens also served in the German Wehrmacht during the Second World War, although purely on an individual and voluntary basis. At least 2,000 Swiss fought for Germany during the war, mostly from the German-speaking cantons of Bern and Zurich, and many of them had dual German nationality. Besides the Wehrmacht some also joined the SS, particularly the 6th mountain division. Due to Switzerland's neutral status, their allegiances were considered illegal and in 1943 the government decided that those who cooperated with Germany would be deprived of their nationality. By 1945, there were only 29 such cases. A number of Swiss citizens were taken prisoner by the Soviet Union while fighting on the Eastern Front.