An explosion at a chemical plant left three people dead and three others slightly injured on Friday in southwest China's Yunnan Province, local authority confirmed Saturday.

The blast occurred around 10:35 AM in Yunnan Dawei Coke Co. Ltd. in Qujing City when workers were maintaining facilities in the workshop.

"The cover for a storage tank was blast off in the violent explosion," a witness said.

Three workers were killed at scene and the injured were rushed to a local hospital.

The cause of the blast is under investigation.

(Xinhua News Agency June 28, 2008)