A missile test off the California coast sparked frenzy on social media and spooked residents who believed they had just seen a UFO.

The Twitter hashtags #Navy, #comet and #UFO were trending as social media users uploaded videos and pictures of the mysterious bright light illuminating the night skies.

"There's a UFO in Los Angeles. I'm so excited. I'm so ready," tweeted Shane Dawson, well known for his YouTube videos.

"Los Angeles UFO? It was not a comet. My son saw the Unidentified Flying Object in Hollywood," tweeted @AnnieJacobsen.

The San Diego Union-Tribune said that the streaking light was visible as far away as Nevada and Arizona and authorities were reportedly flooded with calls.

But just when some were predicting the end of the world, officials moved to clear up the mystery.

"Navy Strategic Systems Programs conducted scheduled Trident II (D5) missile test flight at sea from USS Kentucky, an Ohio Class SSBN, in the Pacific Test Range off the coast of Southern California," Navy Cmdr. Ryan Perry said in a statement to US media.

"The tests were part of a scheduled, on-going system evaluation test."