A shooting at a music festival on the Las Vegas Strip killed at least 20 people and injured over 100, according to media reports.
Las Vegas police on Monday alerted people to avoid the area near the Mandalay Bay Casino on the city's Strip due to reports of an active shooter, media reports said.
Dozens of patrol vehicles descended on the Strip after authorities received reports of an active shooter near the Route 91 Harvest Festival.
Concert-goers reported seeing muzzle flashes from the upper floors of the Mandalay Bay Hotel and Casino across Las Vegas Boulevard from the country music festival and the sound of what they described as automatic gunfire.
Twenty-six people were admitted to the hospital, University Medical Center spokeswoman Danita Cohen said. Of those, at least two died, 12 were in critical condition and the rest were being evaluated, she said.
Witnesses said they saw multiple victims as they fled the gunfire raining down on the concert venue. Some later huddled in the basement of the nearby Tropicana hotel-casino.
Some officers took cover behind their vehicles while others carrying assault rifles ran into the Mandalay Bay Hotel and Casino.
Authorities shut down part of the Las Vegas Strip and Interstate 15.