The sight of an ominous-looking mushroom cloud has frightened the residents of Kemerovo Region in Russia’s Western Siberia, who took to social media networks to show what resembled the distinctive hallmark of a nuclear explosion.

A rare and startling sight sparked the concerns of locals, who feared that an explosion might have occurred at one of the many mines for which the coal-rich Kuzbass is renowned.

“A nuclear war is today in Chusovitino,” @kemerovo_insta wrote.

Ядерная война сегодня в Чусовитино. #kemerovoinsta #кемеровоинста #kemerovo #кемерово Фото опубликовано Кемерово | Kemerovo (@kemerovo_insta) Авг 27 2016 в 9:29 PDT

The others were more cheerful, however.

“A wonder-cloud on the track.”

Чудо #облако на трассе Фото опубликовано Konstantin Suraev (@k.suraev) Авг 27 2016 в 5:29 PDT

@khsy_20_ suggested nature was sending a signal that it’s the time of year to pick mushrooms.

“A mushroom cloud has grown today. This is, probably, a hint that a ‘mushroom season’ is in full swing. It’s time to pick mushrooms. Very beautiful!”

The emergency services were quick to calm down locals, saying that a weirdly-shaped cloud is no more than an ordinary rain cloud being formed. No accidents or ongoing fires were reported that day, Sibnet reported citing local emergencies’ press service as saying.

The natural phenomenon could have been observed in the various parts of the Kuzbass capital, Kemerovo, and in nearby villagers.

👻🌪 Фото опубликовано ✖️O K S✖️ (@oksana_suhoparova) Авг 27 2016 в 4:40 PDT

Фото опубликовано ☀ANASTASIA☀ (@anast_mi) Авг 27 2016 в 12:44 PDT

Вот такое #облако вчера у нас было #облакогриб Фото опубликовано @gingerdaha Авг 27 2016 в 10:36 PDT

Формирование грозовой тучи Фото опубликовано Александра Декина (@alexandra_dekina) Авг 27 2016 в 5:14 PDT

While the view might be mesmerizing, it is not such a rare occasion. On July 18, a phenomenon known as a microburst was captured by photographer Jerry Ferguson over Phoenix, Arizona, from a helicopter.