- Over 50 dead, 400 injured in shooting at Mandalay Bay Hotel in Las Vegas
- The lone gunman has been shot dead, the Las Vegas Sheriff said
- Flights at Mccarran International Airport were temporarily halted
The barrage of gunfire from a 32nd-floor window of the Mandalay Bay hotel into a crowd of 22,000 people lasted several minutes, sparking panic as throngs of music fans desperately cowered on the open ground, hemmed in by fellow concertgoers, while others at the edge tried to flee.
More than 500 people were injured - some by gunfire, some trampled - in the pandemonium adjacent to the Las Vegas Strip as police scrambled to locate the assailant.
Police on Monday identified the gunman as Stephen Paddock, who lived in a retirement community in Mesquite, Nevada. They said they believed he acted alone and did not know why he attacked the crowd. The ISIS terror group claimed responsibility for the massacre, but US officials said there was no evidence of that.
The dead in Las Vegas included a nurse, a government employee and an off-duty police officer.
Shocked survivors, some with blood on their clothing, wandered streets, where the flashing lights of the city's gaudy casinos blended with those of emergency vehicles.
Police said Paddock had no criminal record. The gunman killed himself before police entered the hotel room from where he was firing, Clark County Sheriff Joseph Lombardo told reporters.
"We have no idea what his belief system was," Lombardo said. "I can't get into the mind of a psychopath."
Federal officials said there was no evidence to link Paddock to militant organisations.
US officials discounted the claim of responsibility for the attack made by ISIS in a statement.
"We advise caution on jumping to conclusions before the facts are in," CIA spokesman Jonathan Liu said in an email.
MULTIPLE MACHINE GUNS
Lombardo said there were more than 10 rifles in the room where Paddock killed himself. His arsenal included multiple machine guns, according to a law enforcement official.
US law largely bans machine guns.
Police found several more weapons at Paddock's home in Mesquite, about 90 miles (145 km) northeast of Las Vegas, Mesquite police spokesman Quinn Averett told reporters.
Efforts to pass tougher federal gun laws failed following a number of mass shootings, including the 2012 massacre of 26 young children and educators in Newtown, Connecticut, and the June attack on Republican lawmakers practicing for a charity baseball game.
Nevada has some of the nation's most permissive gun laws. It does not require firearm owners to obtain licenses or register their guns.
House of Representatives Minority Leader Nancy Pelosi, a Democrat, on Monday called on House Speaker Paul Ryan to create a select committee on gun violence.
"Congress has a moral duty to address this horrific and heartbreaking epidemic," Pelosi wrote.
The Second Amendment of the US Constitution protects the right to bear arms, and gun-rights advocates staunchly defend that provision. US President Donald Trump, a Republican, has been outspoken about his support of the Second Amendment.
The White House said on Monday it was too soon after the Las Vegas attack to consider new gun control policies.
"Today is a day for consoling the survivors and mourning those we lost," presidential spokeswoman Sarah Sanders said at a news briefing. "It would be premature for us to discuss policy when we don't fully know all the facts or what took place last night."
Trump said he would travel to Las Vegas on Wednesday to meet with victims, their family members and first responders.
"It was an act of pure evil," said Trump, who later led a moment of silence at the White House in honour of the victims.
The suspected shooter's brother, Eric Paddock, said the family was stunned by the news.
"We're horrified. We're bewildered, and our condolences go out to the victims," Eric Paddock said in a phone interview, his voice trembling. "We have no idea in the world."
He said his brother belonged to no political or religious organisations, and had no history of mental illness. Their father had been a bank robber who for a time was listed on the FBI's "Ten Most Wanted" list of fugitives.
'JUST KEPT GOING ON'
Video of the attack showed panicked crowds fleeing as sustained rapid gunfire ripped through the area as the shooter fired from a distance of around 1,050 feet (320 m).
"People were just dropping to the ground. It just kept going on," said Steve Smith, a 45-year-old visitor from Phoenix, Arizona. He said the gunfire went on for an extended period of time.
"Probably 100 shots at a time," Smith said. "It would sound like it was reloading and then it would go again."
Las Vegas's casinos, nightclubs and shopping draw some 3.5 million visitors from around the world each year and the area was packed with visitors when the shooting broke out shortly after 10 pm local time (0400 GMT).
Shares of MGM Resorts International, which owns the Mandalay Bay, fell 5.58 percent on Monday to $30.77 a share.
Mike McGarry, a financial adviser from Philadelphia, was at the concert when he heard hundreds of shots ring out.
"It was crazy - I laid on top of the kids. They're 20. I'm 53. I lived a good life," McGarry said. The back of his shirt bore footmarks, after people ran over him in the panicked crowd.
(Additional reporting by Jonathan Allen, Chris Michaud and Frank McGurty in New York, Susan Cornwell and Mark Hosenball in Washington, Bernie Woodall in Fort Lauderdale, Florida, Ali Abdelaty in Cairo and Brendan O'Brien in Milwaukee; Writing by Scott Malone; Editing by Grant McCool, Jonathan Oatis and Andrew Hay)