Throughout German-occupied Europe, the Nazis established camps to detain and, if necessary, kill so-called enemies of the state, including Jews, Gypsies, political and religious opponents, members of national resistance movements, homosexuals, and others. Imprisonment in a concentration camp was of unlimited duration, was not linked to a specific act, and was not subject to any judicial review. In addition to concentration camps, the Nazi regime ran several other kinds of camps including labor camps, transit camps, prisoner-of-war camps, and killing centers.