The Russian government is investigating the cause of a shocking sight in Siberia: a river that turned bright red.

Russian social media users posted photos of the blood-red Daldykan River, near the industrial city of Norilsk. The region, located above the Arctic Circle, is home to a factory run by nickel and palladium producer Norilsk Nickel.

In a statement, the Russian ministry of natural resources said it is investigating reports of an unidentified chemical pollution in the river, possibly caused by a Norilsk Nickel pipeline leak.

The statement said the company denies that an industrial leak occurred at the factory.

