ŻZW
Several resistance groups were formed, such as the Jewish Combat Organization (ŻOB) and Jewish Military Union (ŻZW) in the Warsaw Ghetto and the United Partisan Organization in Vilna. Over 100 revolts and uprisings occurred in at least 19 ghettos and elsewhere in Eastern Europe. The best known is the Warsaw Ghetto Uprising in April 1943, when the Germans arrived to send the remaining inhabitants to extermination camps. Forced to retreat on 19 April from the ŻOB and ŻZW fighters, they returned later that day under the command of SS General Jürgen Stroop (author of the Stroop Report about the uprising). Around 1,000 poorly armed fighters held the SS at bay for four weeks. Polish and Jewish accounts stated that hundreds or thousands of Germans had been killed, while the Germans reported 16 dead. The Germans said that 14,000 Jews had been killed—7000 during the fighting and 7000 sent to Treblinka—and between 53,000 and 56,000 deported. According to "Gwardia Ludowa", a Polish resistance newspaper, in May 1943: