The Altmark incident (Norwegian: Altmark-affæren; German: Altmark-Zwischenfall) was a naval incident of World War II between British destroyers and the German tanker Altmark, which happened on 16–17 February 1940. It took place in what were, at that time, neutral Norwegian waters. On board the Altmark were some 300 allied prisoners (officially internees), whose ships had been sunk by the pocket battleship Graf Spee in the Southern Atlantic Ocean. British naval forces cornered the tanker and later the destroyer Cossack attacked the German ship near the Jøssingfjord and freed all the prisoners, killing eight German seamen with firearms and wounding ten others, five of them seriously. A British and a Norwegian sailor were also seriously wounded in the action. Germany claimed that the attack w