Bereza Kartuska Prison (Miejsce Odosobnienia w Berezie Kartuskiej, "Place of Isolation at Bereza Kartuska") was operated by Poland's Sanation government from 1934 to 1939 in Bereza Kartuska, Polesie Voivodeship (today, Biaroza, Belarus). Because the inmates were detained without trial or conviction, it is considered an internment camp or concentration camp. Bereza Kartuska Prison was established on 17 June 1934 by order of President Ignacy Mościcki to detain persons who were viewed by the Polish state as a "threat to security, peace, and social order" or alternately to isolate and demoralize political opponents of the Sanation government such as National Democrats, communists, members of the Polish People's Party, and Ukrainian and Belarusian nationalists. Prisoners were sent to the camp on the basis of an administrative decision, without formal charges, judicial sanction, or trial, and without the possibility of appeal. Prisoners were detained for a period of three months, with the possibility of indefinite extension. Detainees were expected to perform penal labour. Often prisoners were tortured, and at least 13 prisoners died. Besides political prisoners, starting in October 1937 recidivists and financial criminals were also sent to the camp. During the German invasion of Poland in September 1939, the camp guards fled on news of the German advance, and the prisoners were freed. It was created on July 12, 1934, in former Russian barracks and prison at Bereza Kartuska on the authority of a June 17, 1934, order issued by Polish President Ignacy Mościcki. The event that directly influenced Poland's de facto dictator, Józef Piłsudski, to create the prison was the assassination of Polish Minister of Internal Affairs Bronisław Pieracki on June 15, 1934, by the Organization of Ukrainian Nationalists (OUN). It was intended to accommodate persons "whose activities or conduct give reason to believe that they threaten the public security, peace or order.