The Tungchow Mutiny (通州事件 Tsushu jiken, Chinese: 通州事件; pinyin: Tōngzhōu Shìjiàn), sometimes referred to as the Tōngzhōu Incident, was an assault on Japanese troops and civilians by Japanese-trained East Hopei Army in Tōngzhōu, China on 29 July 1937 shortly after the Marco Polo Bridge Incident that marked the official beginning of the Second Sino-Japanese War.
In early 1937, Tōngzhōu was capital of the East Hopei Government, a Japanese puppet state controlling the strategic eastern district of Beijing. In July, a detachment of approximately 800 troops of the Chinese 29th Army, under the command of General Sung Che-yuan and loyal to the Kuomintang government, camped outside the walls of Tōngzhōu. Refusing to leave despite the strong protests of the Japanese garrison commander, the Japanese did not know that General Sung had reached an agreement with East Hopei leader Yin Ju-keng, who hoped to use Sung's Kuomintang troops to rid himself of his Japanese overlords.
On 27 July, the Japanese commander demanded that the Kuomintang soldiers disarm. When they refused, fighting erupted the following day, and the outnumbered and outgunned Chinese troops were trapped between the Japanese and the city wall. However, the Kuomintang Chinese troops' unwillingness to surrender in what was essentially a suicide mission strongly affected the Japanese-trained 1st and 2nd Corps of the East Hopei Army who were attached to the Japanese army. When East Hopei Army units refused to press the attack, Japanese troops bombed their barracks on the evening of 28 July. On midnight of 28 July, some 5000 troops of the 1st and 2nd Corps of the East Hopei Army mutinied, turning against the Japanese garrison. In addition to Japanese military personnel, some 250 civilian residents of Tōngzhōu were killed in the uprising (predominantly Japanese reserves, including police and ethnic Korean-Japanese). According to Japanese sources, the majority of women were raped and some were brutally killed. Only around 60 Japanese civilians survived, but much of the city was destroyed in the fighting.
The massacre shocked public sentiment in Japan, and was used to justify further military intervention for protecting Japanese property and lives in Beijing.