LAS VEGAS -- UPDATE at 6:40 a.m. Authorities in Nevada say at least 50 people are dead and more than 200 hurt when a "lone wolf" gunman opened fire at a country music festival in Las Vegas.

It was previously reported the death toll was at 20+ with more than 100 hurt.

Authorities shut down part of the Las Vegas Strip and Interstate 15 after receiving reports of an active shooter at the Route 91 Harvest festival, near the Mandalay Bay Casino at about 10:10 p.m. local time.

Sheriff Joe Lombardo of Las Vegas Police confirmed at a news conference that the shooter had fired from the 32nd floor of the Mandalay Bay. He said officers responded and the suspect was dead.

PHOTOS | Shooting in Las Vegas

He said the suspect was identified as a local resident, but did not name him.

Lombardo said police were hunting for a person of interest who he named as Marilou Danley. He described her as an Asian female, about 4 foot 11 inches tall and weighing 111 pounds.

He said reports of multiple shooters and explosives were false.

Videos on social media show people ducking for cover and fleeing as gunfire rings out.

Ivetta Saldana, who was attending the festival, told The Las Vegas Review-Journal she hid in a sewer after the shooting began.

“It was was a horror show,” she told the newspaper “People were standing around, then they hit the floor.”

Witnesses said they saw multiple victims and dozens of ambulances. Some concert-goers huddled in the basement of the nearby Tropicana hotel-casino.

Some flights destined for the McCarran International Airport were diverted due to the incident.

The three-day Route 91 Harvest festival started Friday. The shooting occurred on the final night, during a performance by Jason Aldean. Aldean's team confirmed that the star and the rest of his team were safe.