World War II by country throughout the war, as did the international city of Tangier. Nauru was administered by Australia under a League of Nations mandate. Nauru was shelled by a German surface raider in December 1940, aiming to incapacitate its phosphate mining operations (this action was probably the most distant military activity carried out by Germany during the entire war). Phosphates are important for making ammunition and fertilizers. Nauru was occupied by Japan from 1942–45, and was the target of shelling by American battleships and cruisers, and aerial bombing by the Allies. For example, Nauru was bombarded by the American battleships "North Carolina", "Washington",
War crimes in occupied Poland during World War II at Chełmno according to postwar verdict by West Germany, although up to 340,000 victims were estimated by the Polish Main Commission for Investigation of German Crimes in Poland (GKBZNwP), a predecessor of the Institute of National Remembrance. Following the Wannsee Conference of 1942, as part of highly secretive Operation Reinhard in occupied Poland, the German government built three regular killing centres with stationary gas chambers. It was the most deadly phase of the Final Solution, based on implementing semi-industrial means of killing and incinerating people. The new facilities included Treblinka extermination camp (set up in July 1942), Bełżec (March 1942),