Las Vegas, Oct 2 : In one of the deadliest mass shootings in American history, at least 50 people were killed and more than 400 injured as a gunman in a high-rise hotel here opened fire on a huge outdoor concert festival, sending thousands of terrified survivors fleeing for cover.
The gunman, identified by police as local resident Stephen Paddock, was later found dead by officers on the 32nd floor of the Mandalay Bay Hotel and Casino from where he opened fire into the concert, Sheriff Joseph Lombardo said during a news briefing.
The Islamic State group released a statement through its news agency Amaq saying it was behind Sunday night's mass shooting. However, police had previously said that Paddock was not found to be associated with any terrorist activity and described him as a "distressed individual".
Thousands of concertgoers who had gathered for a three-day music festival raced towards shelter when the gunfire began at 10.30 p.m. on Sunday while singer Jason Aldean was performing on stage. Police said over 22,000 people were at the concert when Paddock began firing round after round.
Sheriff Lombardo said Paddock was a "lone wolf" attacker and his body was found in his hotel room by Las Vegas SWAT officers who responded to calls about the shooting, the US media reported.
Recordings of the attack suggested that Paddock used an automatic weapon in the attack. He was found with more than 10 rifles, Lombardo said.
In the initial chaotic aftermath of the shooting, authorities had searched for a woman named Marilou Danley, described as Paddock's "travelling companion". Later, the officials said she had been located out of the country and apparently was not with Paddock when he checked into the hotel.
The gunman was previously known to local police for past run-ins with law enforcement, according to people familiar with the investigation.
US President Donald Trump posted a tweet offering his sympathies to those caught in the Las Vegas attack.
"My warmest condolences and sympathies to the victims and families of the terrible Las Vegas shooting. God bless you!," the President tweeted.
Later, Trump in a short speech from the White House called the attack "an act of pure evil" and will visit La Vegas on Wednesday to meet the families of the victims.
Videos posted on social media showed people screaming and running for cover amid the sound of gunshots that seemed unending.
"We thought it was fireworks at first or trouble with the speakers," said Kayla Ritchie, a concertgoer. "They had been having technical difficulty all weekend. Then everything went dark."
Video from the shooting showed Aldean, the final performer of the night, running off the stage as the gunfire erupted. Jake Owen, a country singer who was on stage with Aldean when the shooting began, told CNN that it was like "shooting fish in a barrel from where he was".
"We heard what sounded like firecrackers going off. Then all of a sudden we heard what sounded like a machine gun. People started screaming that they were hit ... when we started running out there were probably a couple hundred on the ground," said another concertgoer.
"People kept dropping and dropping ... People were getting shot one foot away from us," the eyewitness said. "People were trying to save their friends. There were gunshots everywhere. Helping them would've meant that we got shot too."
Off-duty police officers were among the dead. Two other police officers were also being treated for injuries.
Former presidential candidate Hillary Clinton also tweeted condolences to the Las Vegas shooting victims.
"Las Vegas, we are grieving with you -- the victims, those who lost loved ones, the responders, & all affected by this cold-blooded massacre," she said.
Traders at the New York Stock Exchange also observed a moment of silence for victims of the Las Vegas shooting.