After denying blame for the contamination of the water, Norilsk Nickel said on Monday that a dike at its Nadezhda plant overflowed, colouring the Daldykan river, by the Arctic town of Norilsk, red, CNN reported on Tuesday.
"On the September 5 after abnormal heavy rain, the overflow of one of the dikes occurred, and water entered the Daldykan river," Norilsk Nickel said in a statement.
The company said the "short-term river colour staining with iron salts" presents no hazards for the people and river fauna, and said it will work to avoid such incidents in the future.
Last week, residents shared online images of the river and contacted authorities.
There is a lot of mining near Norilsk, because the area has massive deposits of nickel, copper and palladium, CNN noted.
The region is also known for its heavy pollution.
