Another commented: “It’s a kind of supernatural power flying across the city!”
And a third replied: “Aliens are coming to get us! Scary!”
The dark ring sparked fears of an alien invasion but was likely to be from a firework.
An actual witness speculated that it was a weather event.
They said: “The smoke ring is nothing but a soliton.
“Black hydrocarbon with the vortex making up a ring and lifting it into the air.”
But a weather expert, who remained stumped about what the black ring was, did not agree.
Renad Yagudin of the Siberian Hydrometeorological Centre said: “There is no such definition in meteorology as a soliton.