Mysterious green clouds that floated over Moscow on Thursday, provoked various frightening rumours but later were explained in an ordinary way.

      Photos ans videos of unusually colored clouds appeared on the Internet, where users started to invent the most fantastic versions about that phenomenon. The green substance also colored roads, houses and cars across the capital.

      Because of mystical coincidence with the 26th anniversary of the Chernobyl disaster, the main people's version was some chemical disaster, destroyed factory or nuclear reactor blast. The other popular versions were the secret Government's experiments or even the upcoming Apocalypse. A flood of 911 calls was also registered.

       The Emergencies Ministry advised people to calm down, saying the clouds were actually composed of birch pollen, not of chemicals.

      However, some Internet users still don't believe these words, saying the pollen is just an excuse for the real reasons.

      According to specialists, such stormy birch blooming could be aroused by large temperature drop from very cold beginning of spring to over 20 degrees Celsius in April.

      Birch pollen is also a strong allergen, which increased the suffering of people subject to allergy and asthma. 

Sources: Interfax RIA Novosti utro.ru Image: ria.ru