In fact, the unusually-shaped cloud appeared as a result of a powerful thunderstorm near Kemerovo, western Siberia.
But local residents feared the worst, due to it bearing the symbol of a nuclear explosion, with many calling the emergency services.
Others were concerned that there had been an explosion at a nearby coal mine in the Kuzbass region.
It has been identified as an cumulo-nimbus cloud, which forms when a thunderstorm reaches the highest levels of the atmosphere, causing the top of the cloud to be blown to the side.
Emergency services were inundated with calls from worried onlookers that a nuclear bomb had been dropped and that annihilation was imminent.
Despite wave of fears among the Russians, but the terrifying-looking spectacle was in reality a rather beautiful.