KUNMING - Five people were killed and four others injured after a tank in a cassava processing plant in southwest China collapsed on Tuesday, local authorities said.

The tank for waste water treatment collapsed at around 7 am in a cassava starch processing plant in Simao District, Pu'er City of Yunnan Province, said a local official.

Three died at the scene and two died on their way to hospital. Four others were being treated in a local hospital.

The plant belonged to a local agricultural development company which also produces coffee.

The cause of the accident is being investigated.