Answer:
Many Jews in ghettos across eastern Europe tried to organize resistance against the Germans and to arm themselves with smuggled and homemade weapons. Between 1941 and 1943, underground resistance movements formed in about 100 Jewish groups. The most famous attempt by Jews to resist the Germans in armed fighting occurred in the Warsaw ghetto.
In the summer of 1942, about 300,000 Jews were deported from Warsaw to Treblinka. When reports of mass murder in the killing center leaked back to the Warsaw ghetto, a surviving group of mostly young people formed an organization called the Z.O.B. (for the Polish name, Zydowska Organizacja Bojowa, which means Jewish Fighting Organization). The Z.O.B., led by 23-year-old Mordecai Anielewicz, issued a proclamation calling for the Jewish people to resist going to the railroad cars. In January 1943, Warsaw ghetto fighters fired upon German troops as they tried to round up another group of ghetto inhabitants for deportation. Fighters used a small supply of weapons that had been smuggled into the ghetto. After a few days, the troops retreated. This small victory inspired the ghetto fighters to prepare for future resistance.