The environmental protection department of the Guangxi Zhuang autonomous region warned 12 enterprises over pollution.

The warning follows the Ministry of Environmental Protection's investigation into heavy metal pollution in Guangxi,

The investigating team went to Hechi, Baise, Qinzhou, Yulin, Laibin and Liuzhou recently to check pollution and monitor efforts to tackle it.

The team found pollution levels in Guangxi were serious.