A chemical spill on a river in southern China river has cut water supplies to 20,000 people for at least four days, according to an official Chinese newspaper said Monday.

China Daily reported that a power plant on the upper reaches of the Yuexi River in Sichuan province was to blame for the pollution, which prompted environmental officials to suspend water supplies to Guanyin Town since last Wednesday.

Water was being trucked in to residents, it said.

An employee with a local water supply company noticed the river water had turned yellow last Tuesday, the paper said. Tests showed it was polluted with fluoride, nitrogen and phenol.

The paper did not give the name of the power plant or say when the spill occurred.

The incident follows a spate of spills in recent months, the most serious being an explosion at chemical plant in November that dumped chemicals into the Songhua River, the source of drinking water for tens of millions of people in northeastern China and Russia.