At least 58 people have been killed and hundreds injured in a mass shooting at a Las Vegas concert.
A gunman, named as 64-year-old Nevada resident Stephen Paddock, opened fire from the 32nd floor of the Mandalay Bay Hotel towards an open-air music festival attended by 22,000.
He killed himself as police stormed the room where 10 guns were found.
In an address from the White House, President Donald Trump described the attack as "pure evil".
He praised the efforts of the emergency services, saying their "miraculous" speed saved lives, and announced he would be visiting Las Vegas on Wednesday.
The attack is the worst mass shooting in recent US history.
Paddock's motives remain unclear. Las Vegas Sheriff Joe Lombardo described the shooting as a "lone wolf" attack.
"We have no idea what his belief system was," he said.
So-called Islamic State later claimed to be behind the attack, saying that Paddock had converted to Islam some months ago.
But the group provided no evidence for this and has made unsubstantiated claims in the past.
The FBI says it has made no connection between the attack and any international terrorist group.
Suspected gunman Stephen Paddock
A police statement said the shooting began at 22:08 local time on Sunday (05:08 GMT on Monday). Paddock came from the small town of Mesquite, some 60 miles (100 km) north-east of Las Vegas, and had resided in the hotel since 28 September.
Police in Mesquite have searched his premises and recovered a number of weapons. But they say he had not crossed paths with the police in the past.
Las Vegas police say the number of people injured now stands at 515.
Among those killed was an off-duty police officer.
Earlier, police announced they were seeking a woman, Marilou Danley, in connection with the shooting.
In his latest update, Sheriff Lombardo said she had now been located outside the United States and was not thought to have played any role.
Marilou Danley is believed to have lived with Paddock, and Sheriff Lombardo said he used some of her identity documents to check in to the hotel.
Witnesses reported that hundreds of shots were fired.
Hundreds of people fled the scene and the sound of what appeared to be prolonged automatic gunfire could be heard on videos posted on social media.
Many hotels on the Las Vegas strip close to the scene remained on police lockdown and parts of Las Vegas Boulevard were shut.
Hundreds of concert-goers fled the scene or ducked for cover amid heavy gunfire
A couple at the concert take cover after gunfire was heard at country music festival
People sheltered in hotels, restaurants and at Las Vegas McCarran airport.
A witness, Mike Thompson from London, told the BBC that he saw people running in total panic.
"One man had blood all over him and that's when I knew something was seriously wrong.
"People were running and there was chaos."
Concert-goer Mike McGarry told Reuters he lay on top of his children when the shots rang out.
"They're 20, I'm 53. I lived a good life," he said.
They survived.
Some flights were diverted after news of the incident emerged.
The country music festival had been taking place since Friday at several hotels on the Las Vegas strip.
Singer Jason Aldean, who was rushed off stage when the shooting started, shared on Instagram that he was safe but heartbroken and did not know what to say.
"Tonight has been beyond horrific," he wrote.
"It hurts my heart that this would happen to anyone who was just coming out to enjoy what should have been a fun night."
Nevada has some of the least stringent gun laws in the United States.
People are allowed to carry weapons and do not have to register themselves as a gun-owner.
Background checks are done when people buy guns, but they are also allowed to sell them privately.