Bizarre: blue snow in St. Petersburg

st.petersburg - The inhabitants of the Russian city of St. Petersburg are faced with a big mystery. The streets of the city have been covered with a thick layer of blue snow for a few days. The bizarre phenomenon is recorded on video images.

It is feared that toxic substances in the air are the cause of the blue colored snow. It may be a consequence of the demolition of the pharmaceutical research institute in the city. That is what Nieuwsblad reports.

Experts suspect that the blue color is caused by the chemicals 'cobalt' or 'methylene blue'. Methylene blue is a colorant used in some medical treatments. Researchers have taken samples of the blue substance.

In February 2015, the Russian city of Chelyabinsk was also covered with a thick pack of blue snow. After research, the color turned out to be from dye for Easter eggs. The fabric had ended up in a ventilation system of a factory, after which it was distributed by the neighborhood.