What were these Strange Lights over the ocean off San Diego?

Did you see those strange lights over the waters off of San Diego Monday night?

The hashtags #UFO and #UFOsighting popped up across Twitter Monday as San Diegans blew up the social media platform after spotting mysterious lights in the sky off the coast. Videos and photos show a series of lights in patterns floating high in the sky above the ocean, which were apparently visible for about an hour.

Folks reportedly saw the bright lights as far south as Tijuana, out to Santee and of course near La Jolla.

So what were these strange lights?

San Diego Fire-Rescue told our reporting partner 10 News that the lights were flares. The Coast Guard said the Navy was conducting an exercise with expired flares. But, the Navy has not confirmed this information.