Massive explosion turns night into day over Russia, but what caused it?

Observers have noted that there is an old chemical plant nearby

(YouTube)

Multiple videos have emerged of the night sky over Yekaterinburg, Russia being lit up by an explosion, but no-one's quite sure whether the phenomenon was caused by man or meteor.

A dashcam video dated 11 November shows a driver cruising down a dark road when the sky slowly starts to illuminate, becoming piercingly bright over about 10 seconds before fading back to dark.

It was initially thought that the explosion was caused by an asteroid or comet, which are frequently seen burning up over Russia given its size (and fondness for dashcams).

"It was certainly a good light show," planetary scientist Dr Trevor Ireland told 9News.