While at Tientsin, Doihara, together with Seishirō Itagaki engineered the infamous Mukden Incident by ordering Lieutenant Suemori Komoto to place and fire a bomb near the tracks at the time when a Japanese train passed through. In the event, the bomb was so unexpectedly weak and the damage of the tracks so negligible that the train passed undamaged, but the Imperial Japanese Government still blamed the Chinese military for an unprovoked attack, invaded and occupied Manchuria. During the invasion, Doihara facilitated the tactical cooperation between the Northeastern Army Generals Xi Qia in Kirin, Zhang Jinghui in Harbin and Zhang Haipeng at Taonan in the northwest of Liaoning province.