At least 58 people have been killed and more than 515 injured after a gunman opened fire at a 22,000-strong audience of Country music fans attending a festival in Las Vegas - before killing himself police said.
The death toll, which police emphasized was preliminary and tentative, would make the attack the deadliest mass shooting in US history, eclipsing last year’s massacre of 49 people at an Orlando night club.
The gunman was identified as 64-year-old Stephen Paddock, a local resident, who killed himself after first carrying out the massacre.
There were 22,000 people at the concert that was being held at an outdoor area known as Las Vegas Village, across the Strip from the Mandalay Bay and the Luxor hotels.
Las Vegas Metro Police Sheriff Joseph Lombardo told an early morning press conference the gunfire came from the 32nd floor of the Mandalay Bay, where the Paddock was found dead.
A federal law enforcement official told USA Today that they found a cache of weapons inside the hotel room where Paddock died, where investigators believe he carried out the massacre.
Police have said they do not believe this was an act of terror, but media have described Paddock as “alt-left” and anti-Trump.
Paddock shot himself before police entered the hotel room he was firing from, Clark County Sheriff Joseph Lombardo told reporters.
Earlier reports indicated that Paddock, who had more than 10 rifles in his hotel room, had been shot by police.
The suspected shooter's brother, Eric Paddock, said the family was stunned by the news.
“We have no idea. We’re horrified. We’re bewildered and our condolences go out to the victims,” Eric Paddock said in a brief telephone interview, his voice trembling. “We have no idea in the world.”
Lombardo said the suspect acted alone and was not believed to be connected to any militant group.
“We have no idea what his belief system was,” he said. “Right now, we believe he was the sole aggressor and the scene is static.”
Initially Lombardo said police were interested in his traveling companion, who was also described as his roommate. He named the woman as Marilou Danley. But gave no details of whether she was suspected of involvement in the attack but described her as an “associate.”
It was later suggested in media reports that she had been located. Authorities later on Monday said they no longer regarded her as related to the case, CNN and Fox News reported, citing police sources.
“We are pretty confident there is no longer a threat other than we are attempting to locate the person of interest.
“It’s an ongoing investigation. Right now, we believe he is the sole aggressor at this point.”
US President Donald Trump tweeted his response hours after the incident had happened, offering his condolences to the victims and families of the shooting.
My warmest condolences and sympathies to the victims and families of the terrible Las Vegas shooting. God bless you!
— Donald J. Trump (@realDonaldTrump)
The dead included one off-duty police officer, Lombardo said. Two on-duty officers were injured, including one who was in stable condition after surgery and one who sustained minor injuries, Lombardo said. Police warned the death toll may rise.
Police are still finding people who had taken cover during the attack, Lombardo said. "It's going to take time for us to get through the evacuation phase," Lombardo said.
Police had swarmed the Las Vegas strip late Sunday following reports of multiple shots fired from the Mandalay Bay casino, police and US media reported.
Best-selling country singer Jason Aldean was on stage at the time of the shooting which came towards the end of the concert.
Video footage circulating on social media showed a large crowd enjoying a concert as part of the Route 91 country music festival just outside the casino before what sounded like volleys of automatic gunfire halted the performance.
“We were watching the concert having a great time, then we heard what sounded like firecrackers,” witness Joe Pitz told the local Las Vegas Sun news outlet.
“I guess it was an automatic weapon going off but it literally sounded like firecrackers… Then soon enough there was commotion on the Mandalay Bay side of the stage. They were motioning for medics to come and safety people to come and Jason Aldean ran off the stage.
“Everybody in the vicinity went down. I don't know if they were ducking or if they were but it was chaos.”
A shocked Aldean told his fans via Instagram that he and his band was safe.
“Tonight has been beyond horrific,” the singer wrote.
“I still dont know what to say ... My Thoughts and prayers go out to everyone involved tonight.
“It hurts my heart that this would happen to anyone who was just coming out to enjoy what should have been a fun night.”
In the Twitter footage as people begin to realize what is happening, some crouch down on the ground, while others start to flee.
Police had earlier said they were investigating reports of an active shooter near the Mandalay Bay Casino.
Witnesses speaking to CNN described the scene. “We heard (what) sounded like a glass breaking, so you looked around to see what’s going on and then heard a pop, pop, pop,” Monique Dekerf said. “You’d think for a moment okay we’re fine, there’s no more gunfire, then it starts again.”
Another told the network that it sounded like the “shots were coming from the right side ... it sounded like they were right beside us too ... it was right there.”
This video captured the moment gunshots were heard as the band performed live on stage. First there appears to be confusion as the music suddenly stops, then more gunfire can be heard.
VIDEO: Jason Aldean on stage as a gunman begins to fire upon crowd in Las Vegas
— Al Boe BREAKING NEWS (@AlBoeNEWS)
One Twitter user posted that the casino hotel was on lockdown, while another, citing police scanners, said two gunmen who had shot at a bodyguard and police were on the 32nd floor.
Video clips posted online showed what sounded like automatic weapons as panicked concertgoers fled, dropped to the ground screaming.
Witnesses heard numerous gunshots at the hotel, where police tactical teams were searching for the attacker, according to reports on CNN and in the New York Times.
Video of shooting at Mandalay Bay on LV strip. Pray 4 Las Vegas
— Paul J Duffy (@P_JamesDuffy)
Flights at Mccarran International Airport were temporarily halted after the reported shooting, the airport said on Twitter.
Police have said multiple casualties have been taken to hospital with gunshot wounds.
In this video posted on Twitter people can be seen lying on the ground as bursts of gunfire can be heard.
As people try to flee another burst and people dive to the ground.
THIS IS CRAZY. You can actually hear the gunshots. Please if you are in Las Vegas area take care. Praying for those affected.
— Lady Gaga (@Dominicangaga)
Heavy machine gun fire can be heard on mobile phone footage posted on Twitter.
Active shooter Las Vegas strip I'm ok locked in my room lights off windows closed. Shooter is directly across the street. Shots heard on vid
— Bryan Heifner (@HBryanBHHS)
Further video footage appears to show victims being carried out on makeshift stretchers as a woman in a vehicle is asked to help take the wounded to hospital.
las vegas active shooter
— DNN (@DeplorableNewsN)
(With Reuters, AFP and AP)
