sentences:  After the Marco Polo Bridge Incident a number of Manchukuoan troops deserted to the Anti-Japanese Army.The Northeast Anti-Japanese United Army conducted a protracted campaign which threatened the stability of the Manchukuo regime and the Japanese colonial rule, especially during 1936 and 1937.By the beginning of 1937, it comprised eleven corps in three armies, estimated by the Japanese to be about 20,000 men.