Japanese seizure of the Manchurian city of Mukden (now Shenyang in NE China). A detachment of the Japanese Guandong army, stationed in Manchuria in accordance with treaty rights, used an allegedly Chinese-inspired explosion on the South Manchurian Railway as an excuse to occupy the city of Mukden. Acting without reference to their own government, and in the face of condemnation from the League of Nations, Japanese military authorities then went on to occupy all of Manchuria before the end of 1931, establishing the state of Manchukuo. Japan, labelled an aggressor by the League of Nations, withdrew its membership.