"We're investigating reports of an active shooter near/around Mandalay Bay Casino," police said on Twitter. Several people including a police officer had been shot at a nearby outdoor concert, a local newspaper reported.
The video footage circulating on Twitter purportedly of the Mandalay Bay showed a crowd enjoying a concert before what sounds like volleys of automatic gunfire halt the performance.
Terrifying scene as concert goers attend to injured while gunman opens fire at Mandalay Bay resort in Las Vegas. pic.twitter.com/3bisNIjur2Josh Caplan (@joshdcaplan) October 2, 2017
(Disclaimer: this video contains disturbing images and sounds.)
Las Vegas hospital was taking in "several" people with gunshot wounds, University Medical Center spokeswoman Danita Cohen told the paper.