Demonstrators across the nation, some wearing white masks marked with black crosses, held protests on Saturday to denounce a company accused of contaminating the drinking water of millions.

The scandal, involving the dumping of poisonous wastewater into the Naktong River by a subsidiary of the Doosan Group conglomerate, has aroused intense public ire in a country not usually known for its environmentalism.Demonstrators rallied peacefully in the capital and in the southern cities of Pusan, Taegu, Kwangju and Chonju. Police reported no arrests.

"Let's boycott all Doosan products," about 500 protesters shouted as they marched in Seoul to the company's head office following a rally in a park. Several hundred police walked with the protesters but did not intervene.