The Polish population was subjected to various atrocities. Germans immediately carried out mass arrests of local Polish intelligentsia, activists and officials, who were deported to the Mauthausen concentration camp and murdered there. Germans also carried out massacres of Poles in Gąbin itself, notable examples include an execution of 20 Polish refugees from Pomerania on September 19–21, 1939, an execution of six farmers from nearby villages of Czermno and Strzemeszno in the Gąbin forest in November 1939, a public execution of 10 Poles near the local church on June 15, 1941. Expulsions of Poles and deportations of mostly young Poles to forced labour to Germany were carried out throughout the war. The Germans also burned down the local synagogue, dismantled the Gothic Revival church, which was erected shortly before the war, and destroyed the Polish Tomb of the Unknown Soldier. Despite such circumstances, the Polish underground resistance movement was active in the town. Many Poles from Gąbin were also among the victims of the Katyń massacre.