 The Kwantung Army surrendered to the Soviets the day after the Surrender of Japan and was subsequently dissolved.The Kwantung Army was responsible for many of the worst Japanese war crimes during World War II, including the sponsorship of Unit 731 which performed biological warfare and human experimentation on civilians and prisoners of war.In 1895, Qing China had granted the Kwantung Leased Territory, a valuable concession territory on the Liaodong Peninsula, to the Empire of Japan in the Treaty of Shimonoseki after their victory in the First Sino-Japanese War.