1939 жылғы Польшаға шабуыл кезіндегі Бромберг қырғыны

Massacre in Poland during the 1939 invasion by Nazi Germany

Bloody Sunday (Bromberger Blutsonntag; Krwawa niedziela) was a sequence of violent events that took place in Bydgoszcz (Bromberg), a Polish city with a sizable German minority, between 3 and 4 September 1939, during the German invasion of Poland. Standing in the path of the German army's advance during the early days of the invasion, tensions quickly escalated in Bydgoszcz between the city's sizable German speaking minority and its Polish majority. An instruction issued to the press said, " must show news on the barbarism of Poles against Germans in Bromberg. The expression 'Bloody Sunday' must enter as a permanent term in the dictionary and circumnavigate the globe. For that reason, this term must be continuously underlined." It was Hitler's explicit goal to create a Greater German State by annexing territories of other countries inhabited by German minorities. By March 1939, these ambitions, charges of atrocities on both sides of the German Polish border, distrust, and rising nationalist sentiment in Nazi Germany led to the complete deterioration of Polish German relations. Hitler's demands for the Polish inhabited Polish Corridor and Polish resistance to Nazi annexation fueled ethnic tensions. For months prior to the 1939 German invasion of Poland, German newspapers and politicians like Adolf Hitler had carried out a national and international propaganda campaign accusing Polish authorities of organizing or tolerating violent ethnic cleansing of ethnic Germans living in Poland. After armed conflict erupted on 1 September 1939, ethnic Germans living in Poland were in many places subjected to attacks, and the Polish government arrested ten to fifteen thousand on suspicion of being loyal to Germany, marching them toward the east of the country.

[[File:Bundesarchiv Bild 183 2008 0415 505, Bromberg, Leichen getöteter Volksdeutscher. jpg|300px|thumb|Wehrmacht soldiers and journalists with German victims of Bloody Sunday. The killings were incited by fifth column attacks by ethnic German partisans against the Polish garrison. Besides these sabotage groups in Bydgoszcz, the Abwehr also recorded in its documents paramilitary groups that were formed in the city. According to German records stored in Bundesarchiv Militärarchiv in Freiburg they counted 150 members in Kampf Organisation under leadership of a local German named Kleiss and were part of a larger military formation coordinated from Poznan which altogether had 2,077 members. In addition to this group a 10 member combat unit under command of a German named Otto Meister was also formed in Bydgoszcz and received orders from Wroclaw local office of Abwehr. During the night between 2 and 3 September a number of German saboteurs dressed up in Polish uniforms woke up inhabitants of two districts in Bydgoszcz telling them to run as Poland has been defeated, and as a result a significant number of civilians panicked and started fleeing the city. The chaotic flight disrupted and restricted movements of the Polish military on the roads. By the morning of 3 September a certain few Germans who were in good relationship with their Polish neighbors started warning them to hide as "something bad will happen in the city", offering them shelter under the condition that they must hide by 10 AM, but stated they could not disclose details on what would take place. The Citizen Watch in Bydgoszcz relinquished its weapons after receiving assurances from General Eccard von Gablenz, commander of the Kampgruppe "Netze", that its members would be treated in accordance with international law as POWs.

thumb|upright=1.2|Wochenspruch der NSDAP on 6 September 1942 quotes Dietrich Eckart on the event: "If the light clashes with darkness there is no making of agreements, there is only a fight of life and death until the one or the other part is destroyed." Goebbels' Propaganda Ministry heavily exploited the events to try to gain support in Germany for the invasion. As British historian Ian Kershaw wrote:

Hitler's secret decree of 4 October 1939 stated that all crimes committed by the Germans between 1 September 1939 and 4 October 1939 were not to be prosecuted. The Wehrmacht War Crimes Bureau investigation in 1939–1940 claimed that the events were a result of panic and confusion among the Polish troops. Additionally, in the Zbrodnia w Boryszewie fifty Polish prisoners of war from Bydgoszcz were accused by Nazi summary courts for taking part in "Bloody Sunday" and shot. According to a German version, Polish snipers attacked German troops in Bydgoszcz for several days (Polish sources and witnesses do not confirm this). More than 20,000 Polish citizens of Bydgoszcz (14% of the population) were either shot or died in concentration camps during the occupation. This debate has been resolved by investigation of German archives, which confirmed existence of several diversion and saboteur groups in Bydgoszcz overseen by intelligence organizations by Nazi Germany. Among the Germans killed in the fighting historians identified Otto Niefeldt who was an Abwehr agent from Szczecin. In the post war collaboration trials, no ethnic German was charged in relation to Bloody Sunday.). The Poles retaliated, killing many and executing prisoners afterwards. In 2004, historian Tomasz Chinciński in a publication of Institute of National Remembrance (IPN) summarized recent research related to Bloody Sunday, confirming that the majority of historians agree that an "insurrection" by agents who had arrived from the Third Reich as well as some German inhabitants of Bydgoszcz took place.