It was an unusual glare dominating the skyline last Friday over Moscow.

Photos, video and rumours flew on Twitter and Facebook about what looked like a green ash cloud hanging above the city .

Last week was the anniversary of the 1986 Chernobyl nuclear disaster in the Ukraine, which had people on edge.
Officials say that the ash cloud was actually a cloud of pollen from birch trees.

Conditions have been been dry and warm for the past week in Moscow. With dry weather, pollen accumulates on leaves. With a sudden gust of wind, pollen can shake loose.

WW and Accuweather