The gunman, who has been named as 64-year-old Stephen Paddock, is reported to have opened fire at an open-air country music festival at the Mandalay Bay Hotel on the city’s strip.
A University Medical Centre spokeswoman told the LA Times that the hospital was still evaluating the condition of many patients in the wake of the shooting, with at least 14 people reported to be in “critical condition”.
Police have also reported that one suspect has been "taken down".
Jeff Clark, sergeant of the Las Vegas Metropolitan Police, told reporters at the scene: “We do have one suspect down, and we want people to steer clear of the area.”
The police later tweeted that they “do not believe there are any more shooters”.
Video footage shared on social media shows hundreds of people fleeing from the scene of the three-day Route 91 Harvest country music festival and the sound of what appears to be gunfire can be heard in some clips.
Police have shut down the area and urged the public to stay away, while some flights in and out of Las Vegas airport were temporarily halted.
