Jewish partisans were fighters in irregular military groups participating in the Jewish resistance movement against Nazi Germany and its collaborators during World War II. A number of Jewish partisan groups operated across Nazi-occupied Europe, some made up of a few escapees from the Jewish ghettos or concentration camps, while others, such as Bielski partisans, numbered in the hundreds and included women and children. They were most numerous in Eastern Europe, but groups also existed in occupied France and Belgium, where they worked with the local resistance. Many individual Jewish fighters took part in the other partisan movements in other occupied countries. In total, the Jewish partisans numbered between 20,000 and 30,000.