GUANGZHOU - A kaoline plant is to blame for water pollution that caused death of huge amount of fish in South China's Guangdong province, local environment authorities confirmed Monday.

Huazhou-based Deying Kaoline Plant has been illegally discharging untreated acid waste water to the Longwo River close to the village of Longtan, the Guangdong Provincial Department of Environmental Protection said in a statement after an investigation.

Local residents complained on Sunday via Internet postings that huge amount of fish died as a result of water pollution.

The postings also said thousands of residents along the river were affected by the pollution, and some began to store up bottled water.

The provincial environmental protection department has since ordered the local government to halt the discharging of waste water from the plant and use lime to neutralize the contaminated water.

By Monday evening, water quality in the Longwo River has been improved and the Hedi Reservoir, a drinking water resource in the lower reaches of the river, is in normal condition, said the statement.

The Guangdong provincial environmental monitoring center also enhanced surveillance on water quality in the area, it said.