Many Jews were victims of the Holocaust in France. Approximately 49 concentration camps were in use in France during the occupation, the largest of them at Drancy. In the occupied zone, as of 1942, Jews were required to wear the yellow badge and were only allowed to ride in the last carriage of the Paris Métro. 13,152 Jews residing in the Paris region were victims of a mass arrest by pro-Nazi French authorities on 16 and 17 July 1942, known as the Vel' d'Hiv Roundup, and were transported to Auschwitz where they were killed.