Despite the nominal truce, numerous violations of the ceasefire continued, including another shelling of Wanping by Japanese artillery on 14 July 1937. By 25 July, Japanese reinforcements in the form of the
IJA 20th Division arrived and fighting reerupted first at
Langfang, a city on the railroad between Beijing and
Tianjin, between companies of Japanese and Chinese troops. A second clash occurred on 26 July 1937, when a Japanese brigade attempted to force its way through Guanghuamen Gate in Beijing to "protect Japanese nationals". The same day Japanese planes bombed
Langfang. The Japanese then issued an ultimatum to General Song demanding the withdrawal of all Chinese forces from the outskirts of Beijing to the west of the
Yongding River within 24 hours. Song refused, ordered his units to prepare for action, and requested large reinforcements from the central government, which were not provided. On 27 July 1937, as the Japanese laid siege to Chinese forces in
Tongzhou, one Chinese battalion broke out and fell back to . Japanese planes also bombed Chinese forces outside Beiping and reconnoitered
Kaifeng,
Zhengzhou and
Luoyang. On the same day
Emperor Hirohito sanctioned an imperial order to bring stability to the strategic areas in the region. On 28 July 1937, the
IJA 20th Division and three independent combined brigades launched an offensive against Beijing, backed by close air support. The main attack was against Nanyuan and a secondary attack against
Beiyuan. Bitter fighting ensued with both General
Tong Linge Deputy Commander of Chinese 29th Army and General
Zhao Dengyu commanding Chinese 132nd Division being killed, and their units suffering heavy casualties. However, a brigade of Chinese 38th Division under General
Liu Chen-san pushed back the Japanese in the Langfang area while a brigade of the Chinese 53rd Army and a portion of the Chinese 37th Division recovered the railway station at
Fengtai. However, this was only a temporary respite, and by nightfall General Song admitted that further combat was futile and withdrew the main force of Chinese 29th Army south of the Yungging River. Tianjin Major General
Zhang Zizhong was left in Beiping to take charge of political affairs in
Hebei and
Chahar provinces with virtually no troops. General Liu Ruzhen's New Separate 29th Brigade was left in Beijing to maintain public order. ==Tongzhou mutiny==