The Zhejiang-Jiangxi campaign or the Chekiang–Kiangsi campaign (Japanese: 浙贛作戦, simplified Chinese: 浙赣战役; traditional Chinese: 浙赣戰役; pinyin: Zhè-Gàn Zhànyì), also known as Operation Sei-go (Japanese: せ号作戦), was a campaign by the China Expeditionary Army of the Imperial Japanese Army under Shunroku Hata and Chinese 3rd War Area forces under Gu Zhutong in Chinese provinces of Zhejiang and Jiangxi from mid May to early September 1942.
Japanese troops used biological weapons against Chinese soldiers and civilians alike. Japanese soldiers also committed massacres throughout the battle, resulting in over 300,000 Chinese deaths. Shunroku Hata, the commander of Japanese forces involved in the massacre of the 250,000 Chinese civilians, was sentenced in 1948 in part due to his "failure to prevent atrocities". He was given a life sentence but was paroled in 1954 after only serving six years.