of the local Jews. By 1 October 1940, the relocation of the ghetto inmates was to have been completed, and the city's downtown core declared Judenrein (cleansed of its Jewish presence). The German occupiers pressed for the ghetto size to be shrunk beyond all sense in order to have their factories registered outside of it. Łódź was a multicultural mosaic before the war began, with about 8.8% ethnic German residents on top of Austrian, Czech, French, Russian and Swiss business families adding to its vibrant economy. The securing of the ghetto system was preceded by a series of anti-Jewish measures as well as anti-Polish measures meant to inflict terror. The Jews were forced to wear the yellow badge. Their businesses were expropriated by the Gestapo. After the invasion of Poland, many Jews, particularly the intellectual and political elite, had fled the advancing German army into the Soviet-occupied eastern Poland and to the area of future General Government in the hope of the Polish counter-attack which never came. On 8 February 1940, the Germans ordered the Jewish residence to be limited to specific streets in the Old City and the adjacent Bałuty quarter, the areas that would become the ghetto. To expedite the relocation, the Orpo Police launched an assault known as "Bloody Thursday" in which 350 Jews were fatally shot in their homes, and outside, on 57 March 1940. Over the next two months, wooden and wire fences were erected around the area to cut it off from the rest of the city. Jews were formally sealed within the ghetto walls on 1 May 1940. As nearly 25 percent of the Jews had fled the city by the time the ghetto was set up, its prisoner population as of 1 May 1940 was 164,000. Over the coming year, Jews from German-occupied Europe as far away as Luxembourg were deported to the ghetto on their way to the extermination camps. A small Romany population was also resettled there. By 1 May 1941, the population of the ghetto was 148,547. Ghetto policing To ensure no contact between the Jewish and non-Jewish populations of the city, two German Order Police battalions were assigned to patrol the perimeter of the ghetto, including the Reserve Police Battalion 101 from Hamburg. Within the ghetto, a Jewish Police force was created to ensure that no prisoners tried to escape. On 10 May 1940 orders went into effect