The units of the 3rd Area Army proved to be no match for the Red Army when the Soviet Union invaded Manchukuo towards the end of World War II. General Jun Ushiroku refused orders from Kwantung Army Headquarters to retreat, and launched a counterattack along the Mukden–Port Arthur railway, along which many Japanese civilians were fleeing. However, General Uchiroku was hampered by lack of armor and by insufficient ammunition, and by August 13, 1945, his formations were largely shattered. A mutiny by the Manchukuo Imperial Army at Shinkyō ended his attempts to regroup. Many surviving soldiers of the 3rd Area Army, including General Ushiroku, became prisoners in Siberia and other parts of the Soviet Union after the surrender of Japan on August 15, 1945.