13 de abril de 1941.

"The discovery of a mass grave of Polish prisoners-of-war executed by Soviet forces in the Katyń Forest Massacre was announced in Germany, driving a wedge between the Western Allies, the Polish government-in-exile in London, and the Soviet Union. The Katyn massacre, also known as the Katyn Forest Massacre and the Katyn Incident (Polish: Katyń), was a mass execution of Polish citizens by the order of Soviet authorities in 1940. Estimates of the number of Polish citizens executed at three mass-murder sites in the spring of 1940 range from some 1803 through 14,540,and through 21,857 to 27,700. Most of those killed were reserve officers taken prisoner during the 1939 Polish September Campaign, but the dead also included many civilians who had been arrested for being "intelligence agents and gendarmes, spies and saboteurs, former landowners, factory owners and officials". Since Poland's conscription system required every unexempted university graduate to become a reserve officer, the Soviets were thus able to round up much of the Polish, Jewish, Ukrainian and Belarusian intelligentsias of Polish citizenship. "

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