Manhattan’s night sky resembled something from a doomsday film on Thursday night when a gas explosion bathed the city in eerie light, causing some to fear an alien invasion.

New Yorkers were stopped in their tracks by the flickering light which was accompanied by a loud hum and plumes of smoke just after 9.12pm [local time].

La Guardia Airport was plunged into darkness, grounding planes, while nearby Rikers Island prison complex, which houses 10,000 inmates, lost power for more than 20 minutes.

In some areas of the city, the explosion made it look like the middle of the day, with some people running for safety.

Astoria resident Peter Dipietrantonio told the New York Times he saw people rushing down the street.

Here are a couple more amazing photos of the night sky in New York City. Incident at #Astoria power plant or #alieninvasion? You decide. pic.twitter.com/3PFSDBZdOR

— Oren Segal (@orensegal) December 28, 2018

“Once we saw people running, we decided to get out,” he said. His girlfriend, Dana Jefferson, stood on the street, carrying the duffel bag she had quickly packed. “She was ready to go,” he said.

“We thought it was a UFO,” said Yiota Androtsakis, a longtime Astoria resident.

Something insane is happening in the sky above Manhattan right now. pic.twitter.com/elCqFLF0iU

— Eric Klinenberg (@EricKlinenberg) December 28, 2018

Authorities confirmed the unnatural shade of blue was caused by a transformer explosion at a Con Edison substation in Astoria, Queens.

But many New Yorkers took to social media to speculate extraterrestrial sources were responsible for the eerie light show.

“Damn, all those sci-fi movies were right, aliens always attack New York first for some reason,” one Twitter user wrote.

“Aliens attacking the Empire State Building or power plant transformer fire in Queens?”

Con Edison, one of the city’s major energy suppliers, issued a statement saying the blue light was caused by a sustained electrical arc flash — the same arcs which create lightning.

What is happening in the sky in New York! Any ideas?! pic.twitter.com/cOen3Cqdy6

— Jack Webb-Heller (@JackWH21) December 28, 2018

https://twitter.com/kiaraalfonseca/status/1078475266601730050

The bright lights and bangs caused a surge in 911 calls, prompting the New York Police Department to inform New Yorkers that aliens were not taking over their city.

“No injuries, no fire, no evidence of extraterrestrial activity,” the New York Police Department tweeted.

Blue skies in New York, what’s going on? 😱 pic.twitter.com/yBPKeYeh44

— Andres Rios (@andressrrios) December 28, 2018

What is going on with the sky in New York City? #nyc #greensky pic.twitter.com/3TTZx8E0HI

— Aditya Sharma (@adityasharmac) December 28, 2018

One police officer at the nearby 114th Precinct told the New York Times the explosion was “spectacular”.

“You could see it from the precinct, and the precinct is about a half-mile away,” Deputy Inspector Osvaldo Nuñez said. “You felt it in your chest, the explosions, and the night sky turned an electric blue.”

In one video, a frightened woman can be heard telling a friend not to get any closer to the flashing lights and to call 911.

Miraculously, no one was injured in the explosion.

Ebony Bowden contributed reporting from New York City.