Masuria. A consequence of Operation Vistula was the almost total depopulation of Pogórze Przemyskie, Bieszczady and Beskid Niski coupled with the forcible repatriation of Ukrainians from Poland to the Soviet Union (the Ukrainian SSR and Siberia) in 1944–46. The relocation of the population put the UPA forces in Poland in the most difficult position; deprived of human and other resources, the outnumbered Ukrainian partisans were unable to uphold their armed resistance against the communist forces. Nevertheless, the UPA remained active for a few more years. After the last relocations, UPA's activities on Polish territory died out. Some Ukrainian partisans fled to Western Europe, notably to West Germany, and the United States. Process of Deportation A principle of 'collective responsibility' was applied, all Ukrainians within the indicted area of Poland were deported regardless of political leanings, alliances and historical affiliations. Polish authorities decided to resettle "every person of Ukrainian nationality". Mixed families, communities that did not support UPA, Lemkos returning from Red Army service, "even loyal party members trained in the Soviet Union, even communists who helped 'repatriate' Ukrainians in the previous wave, were forcible resettled". Nationality was not decided by 'individual choice' but by religion, language and "frequently by the letter 'U' in the Kennkarte Polish citizens received from the Nazi occupation during the war". Those who resisted deportation were imprisoned in the Jaworzno prison camp in Silesia. In total 3,936 Ukrainians were imprisoned in Jaworzno camp, a war time affiliate of the Auschwitz-Birkenau complex. Of the near 4,000 Ukrainians taken to Jaworzno camp, 823 were women and children, torture, typhus epidemics and additional exigencies resulted in the several deaths and suicides in the camp. Military tribunals were also to judge civilians and sentenced to death 173 Ukrainians on the spot during Operation Vistula. The Ukrainians were transported in compact cattle and box cars, sanitary conditions were poor and food supplies irregular, some deportees died during transit. Ukrainians were packed into trains for Lublin or Oswiecim, where they were rerouted to their places of settlement. The final destination and degree of dispersal of groups was determined by the judgement of the intelligence officers, whose colleagues were waiting to receive their instruction in sealed envelopes at the end of the line. Events The deportations occurred in stages. Poland and the Soviet Ukraine conducted population exchanges resulting from bilateral agreements signed on 1944 and 16 August 1945. The first transfers occurred at