Soviet partisans in Poland

Poland was annexed and partitioned by Germany and the Soviet Union in the aftermath of the invasion of Poland in 1939. In the pre-war Polish territories annexed by the Soviets (Western Ukraine, Western Belarus, Lithuania and Białystok regions, known to Poles as "Kresy") the first Soviet partisan groups were formed in 1941, soon after Operation Barbarossa, the German invasion of the Soviet Union. Those groups fought against the Germans, but conflicts with Polish partisans were also common.

Initially the Soviet partisan groups were formed primarily in the areas of Nowogródek (modern Navahrudak), Lida and Wilno (modern Vilnius) from Red Army soldiers who evaded capture by the advancing German forces. Lacking support from the local population, the Soviet partisan groups retreated to various large forest complexes in the area, where they hid from the German rear and anti-partisan units.

Until early 1943, the Soviet partisans focused primarily on survival deep behind enemy lines, with their activity limited mostly to sabotage and diversion rather than armed struggle against German forces and collaborationist police units. During this early period various Soviet partisan groups also collaborated with the local Polish resistance of ZWZ, later renamed the AK. The Polish underground was established in the area in the fall 1939. Polish resistance was both anti-Nazi and anti-Soviet; their attitude represented the fact that both powers had invaded Poland, and Polish citizens suffered from Soviet terror just as they did from Nazi terror. There was no love lost between Polish and Soviet resistances, as Joseph Stalin's goal was to prevent a reemergence of an independent Poland after the war.

...
Wikipedia