NEW YORK - A transformer explosion at an electric power substation in the New York City borough of Queens lit up the night sky with a bright blue light on Thursday, mystifying some residents, but officials said no one was injured in the incident.

"There was a boom and a bang and a flash of light," said Jim Long, a spokesman for Fire Department New York.

"It's all under control but we're still getting calls from residents wondering what happened," he said early on Friday.

The blue flashes that briefly lit up the night sky in the Astoria area of Queens, New York, shortly after 9 pm local time were caused by a power surge and electrical "arching" and sparked a transformer explosion and a small fire, said Con Edison spokesman Bob McGee.

There were no injuries, he said. Social media lit up with videos and photos of the bright light in the night sky over New York City. The chatter continued into Friday morning.

"Why is the sky lit up bright blue in Queens New York City right now? Is it fireworks?" Louis Santoro, a New York City resident, wrote on Twitter.