since 5 November, General Ma declined a Japanese ultimatum to surrender Qiqihar. On 17 November, in subzero weather, 3,500 Japanese troops, under the command of General Jirō Tamon, mounted an attack, forcing General Ma from Qiqihar by 19 November. Operations in Southern Northeast China In late November 1931, General Honjō dispatched 10,000 soldiers in 13 armored trains, escorted by a squadron of bombers, in an advance on Chinchow from Mukden. This force had advanced to within of Chinchow when it received an order to withdraw. The operation was cancelled by Japanese War Minister General Jirō Minami, due to the acceptance of modified form of a League of Nations proposal for a "neutral zone" to be established as a buffer zone between China proper and Manchuria pending a future Chinese-Japanese peace conference by the civilian government of Prime Minister Baron Wakatsuki in Tokyo. However, the two sides failed to reach a lasting agreement. The Wakatsuki government soon fell and was replaced by a new cabinet led by Prime Minister Inukai Tsuyoshi. Further negotiations with the Kuomintang government failed, the Japanese government authorized the reinforcement of troops in Manchuria. In December, the rest of 20th Infantry Division, along with the 38th Mixed Brigade from the 19th Infantry Division were sent into Manchuria from Korea while the 8th Mixed Brigade from the 10th Infantry Division was sent from Japan. The total strength of the Kwantung Army was thus increased to around 60,450 men. With this stronger force, the Japanese Army announced on December 21, the beginning of large-scale anti-bandit operations in Manchuria to quell a growing resistance movement by the local Chinese population in Liaoning and Kirin provinces. On December 28, a new government was formed in China after all members of the old Nanjing government resigned. This threw the military command into turmoil, and the Chinese army retreated to the south of the Great Wall into Hebei province, a humiliating move which lowered China's international image. Japanese forces occupied Chinchow on January 3, 1932, after the Chinese defenders retreated without giving combat. Occupation of northeast China With southern Manchuria secure, the Japanese turned north to complete the occupation of Manchuria. As negotiations with Generals Ma Zhanshan and Ting Chao to defect to the pro-Japanese side had failed, in early January Colonel Kenji Doihara requested collaborationist General Qia Xi to advance his forces and take Harbin. The last major Chinese regular force in