The light was seen across the capital including in Islington, Dagenham and Collier Row yesterday (November 19).
Photographs show a beam of blue light directed into the clouds, which was widely reported as blue but also as changing colour.
Explanations from aliens to the bat signal were offered up, but most pointed to an exhibition of lights as the likely explanation.
The LIGHT 25 exhibition runs from November 19 to 20 at London’s Business Design Centre in Angel showcasing architectural and decorative lighting.
Advertisements for the event show a blue beam being shone into the sky, like the one seen across London.
Those who attended the event have also shared close-up pictures of a laser, called the “Sky Laser”.
One person commented: “Glad it’s not aliens, I’ve got plans this weekend.”
