Three men were detained Monday for dumping garbage in a river that caused a massive tap water pollution in Chengdu, capital of southwest China's Sichuan Province, police said.

Liu Decheng, Liu Tao and Li Bo, all from Tianma Town in Dujiangyan City in Sichuan, admitted to have dumped 4 tonnes of solid wastes in Baimu River, source of drinking water for Chengdu city, police said.

Further investigation is still underway, police said.

Tap water supply to parts of Chengdu was turned off for hours Friday noon after the pollution incident took place. Water supply resumed at 11 p.m. the same day.

The garbage was fished up by Saturday morning. Tests in the past several days indicated the water in Baimu river is safe, a spokesman with Chengdu water resources department said.