World War II communists launched an offensive in Central China; in retaliation, Japan instituted harsh measures in occupied areas to reduce human and material resources for the communists. Continued antipathy between Chinese communist and nationalist forces culminated in armed clashes in January 1941, effectively ending their co-operation. In March, the Japanese 11th army attacked the headquarters of the Chinese 19th army but was repulsed during Battle of Shanggao. In September, Japan attempted to take the city of Changsha again and clashed with Chinese nationalist forces. German successes in Europe encouraged Japan to increase pressure on European governments in Southeast Asia. The Dutch government
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),