Altona Bloody Sunday (German: Altonaer Blutsonntag) was the name given to a violent confrontation between the Sturmabteilung (SA) and Schutzstaffel (SS), the police, and Communist Party (KPD) supporters on Sunday 17 July 1932 in Altona, now in Hamburg but then part of Schleswig-Holstein, a province of Prussia. The riots left 18 people dead.