GUANGZHOU - Government authorities of Fengkai County, south China's Guangdong Province, on Saturday warned that water in a section of the Hejiang River has been tainted by pollution upstream.

Around 6 a.m. Saturday, dead fish were found in a section of the river in Fengkai County after hazardous substances had been detected upstream in neighboring Guangxi Zhuang Autonomous Region, the county government said.

The county government has warned the local tap water plant and residents against taking water or eating aquatic products from the Hejiang River.

Investigation is under way to determine the pollutants and their source.