An explosion rocked a workshop at a chemical plant in the city of Jiujiang, east China's Jiangxi Province on Sunday, CCTV reported citing local authorities.

The number of casualties was not immediately clear.

The blast took place at 05:00 p.m. local time (0900 GMT) in Jiujiang Zhijiang Chemical Co., Ltd. in Pengze County Industrial Park.

Residents living around the area were evacuated and rescue operation is underway.

The cause of the blast is still under investigation.