The South Manchuria Railway had been controlled by Japan since the end of the Russo-Japanese War, but the relationship between the local Chinese population and the Japanese soldiers who guarded the line was tense. Following the onset of the Great Depression, some renegade members of the Japanese Kwantung Army believed that a conflict in the area would be beneficial for Japan.
Japanese troops detonated a small quantity of dynamite near the tracks at around 10.20pm on the evening of 18 September. The explosion caused such little damage to the railway line that a train was able to travel over the same section of track ten minutes later without any problems. Despite having carried out the explosion themselves, the Japanese blamed Chinese rebels for the blast. Within hours the resident Japanese forces had driven a nearby Chinese garrison from their barracks in apparent retaliation for the alleged attack.
Over the next few days the Japanese army took control of towns and cities along the entire railway line, acting independently of the government in Tokyo. The politicians, unable to rein in the army, eventually lent their support and sent additional troops to support the invasion.
The Chinese government appealed to the League of Nations for assistance, and the League promptly passed a resolution calling for the withdrawal of Japanese troops. Japan ignored the League, and ruled Manchuria as a puppet state.
