'Bullets flying everywhere': Active shooter opening fire at Vegas hotel

A Seven News reporter is at the scene where a gunman opened fire at a hotel in Las Vegas with reports emerging of several casualties.

US correspondent Ashlee Mullany was only a few floors away as the shooter opened fire at the Mandalay Bay Casino.

Mullany was among a large number of evacuees and will report on the unfolding incident at 6pm Sydney time.

Video shot from a nearby high-rise building shows the crowd at the festival appearing to flee in panic.

The crowd quickly disperses for the exit.

A witness told News 3 Las Vegas said there were "bullets flying everywhere".

"We were on the furthest VIP stages away from Mandalay Bay and they were ricocheting everywhere we were," he said.

"They were firing from somewhere high and they were unloading clip, after clip, after clip."

The New York Daily News reports the feared gunfire erupted just after 10 pm during the Route 91 Harvest country music festival.

Gunshot victims are being transported to hospitals.

University Medical Center spokeswoman Danita Cohen said the Las Vegas hospital is taking in “several” people with gunshot wounds. She didn’t have any more immediate information.

Part of the Las Vegas Strip has been shut down.

Officer Aden Ocampo-Gomez says deputies are heading to the scene Sunday near Mandalay Bay Hotel and Casino.

No further information was immediately known.

More to come.