PRESS ASSOCIATION-- University Medical Centre spokeswoman Danita Cohen said 26 people had been admitted to the hospital. Of those, at least two had died and 12 were in a critical condition. The rest are being assessed.
Dozens of patrol vehicles descended on the Strip after authorities received reports of an active gunman near the Route 91 Harvest Festival.
Some officers took cover behind their vehicles while others carrying assault rifles ran into the Mandalay Bay Hotel and Casino.
Authorities shut part of the Las Vegas Strip and Interstate 15.
Concert-goers reported seeing muzzle flashes from the upper floors of the Mandalay Bay hotel-casino across Las Vegas Boulevard from the music event and the sound of what they described as automatic gunfire.
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 flights destined for McCarran International Airport were diverted due to the incident.