Russian emergency workers have flown to a Siberian region where smelly orange, yellow and green snow fell.

The Emergency Situations Ministry said officials in the Omsk region, about 1,400 miles east of Moscow, had warned local residents not use the snow for drinking or other purposes, and to keep domestic animals from it.

The ministry said the snow, which fell on Wednesday afternoon, was yellow, green and orange and had an oily texture and unpleasant smell.

More than 27,000 people live in the area where the snow fell, but no health problems have yet been reported, the ministry said.

RIA-Novosti quoted an emergency official in the adjacent region of Tyumen, west of Omsk, as saying coloured snow had fallen there as well.