The period between July and September 1942 saw mass deportations of Warsaw ghetto inhabitants. In light of these deportations and the foreseeable evacuation of the rest of the ghetto, Jewish resistance fighters established the Jewish Fighting Organization (ŻOB), while right-leaning Zionists formed the Jewish Military Union (ŻZW). When the SS and the police launched a new deportation campaign on January 18, 1943, they were confronted with armed Jewish resistance for the first time. Although approximately 6,500 ghetto inhabitants were captured, deported to Treblinka, and murdered there, the resistance did manage to halt the deportations, at least temporarily. As part of a so-called “large-scale operation” [Großaktion] ordered by Ferdinand von Sammern-Frankenegg (1897-1944), leader of the SS and police in Warsaw, plans were made to clear the entire ghetto in April. At the start of the operation, Sammern-Frankenegg was replaced by Jürgen Stroop (1895-1951). According to estimates in the Stoop Report, roughly 12,000 to 13,000 Jews were killed during the suppression of the Warsaw ghetto uprising (April 19 to May 16, 1943). Around 50,000 ghetto inhabitants were captured during the operation and deported to various death and extermination camps (7,000 to Treblinka, and around 15,000-18,000 to Majdanek). Others were sent to labor camps, especially Poniatowa and Trawniki.