A river in the world’s northernmost city has turned bright red. This change in the Daldykan River’s color may be related to pollution from the nearby Nadezhda Metallurgical Plant, which processes nickel concentrate, reports the Siberian Times.

The plant, along with most other factories in the industrial city of Norilsk, is owned by the mining and metallurgical company Norilsk Nickel. For now, Norilsk Nickel will not confirm any industrial waste leakage, although they say they are undertaking environmental monitoring in the area.

Meanwhile, locals say that this isn’t the first time the river has turned red, and have begun sharing pictures of the Daldykan’s stunning new hue on social media.

[H/T Atlas Obscura]