In January 1943 , out of 56,000 partisan personnel , 11,000 operated in western Belarus , 3.5 fewer per 10,000 local people than in the east , and even more so ( up to a factor of 5 to 6 ) if one accounts for much more efficient Soviet evacuation measures in the east during 1941 . Smallholders in the west showed " surprising " sympathies to the partisans . Polish author Jerzy Turonek argues that Soviet authorities deliberately refrained from a larger accumulation of partisan forces in western Belarus and let Polish underground military structures grow in these lands during 1941-1942 in order to strengthen Moscow 's relations with the Polish government-in-exile of Władysław Sikorski . A certain level of military cooperation , imposed by the command headquarters , was noted between Soviet partisans and the Polish Home Army , '' Armia Krajowa '' ( AK ) . Soviet partisans avoided to some extent attacking people of Polish nationality during the terror campaigns in 1942 . After the breakdown of diplomatic relations between the USSR and the Polish government-in-exile in April 1943 resulting from the discovery of the Katyn massacre ( which the Katyn Commission of April-May 1943 attributed to the Soviets ) , the situation changed radically . From this moment on , Moscow treated the AK as a hostile military force
Katyn massacre
Katyn massacre
Soviet partisans