A mysterious fall of yellow snow in the Omsk region of Siberia has had locals worried, but officials says it is not toxic.

The snow has been described as having a "distinctive smell", and being yellow "with oily marks". The Russian media has speculated that the snow fall could have been caused by a chemical accident in Siberia, an apparently plausible hypothesis: Omsk is a heavily industrialised region, with several oil and gas refineries.

But despite concern about toxic spills, tests have apparently come back clear. Reuters reports that Russia's emergency ministry flew a chemical lab to the region to analyse the dodgy precipitation.

Regional emergency spokesman, Vladimir Gurzhei, said: "Yellow snow that fell on Omsk region two days ago poses no threat to people's health."

The Russian media's newfound yellow snow experts have also suggested that the phenomenon could have been caused by a rare dust storm in contiguous Kazakhstan.

Since the snow seems to have fallen from the sky in its yellow state, we sadly have to discard our own pet theory that thousands of oil refinery workers decided to put their secondhand beers to good use in a large scale, late night, drunken pee-a-thon. ®

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