More than 50 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.

Police say he killed himself as officers stormed the room where 10 guns were found. The attack is the worst mass shooting in recent US history.

US President Donald Trump tweeted his “warmest condolences and sympathies” to the victims and their families, and called the shooting “terrible”.

Sheriff Joe Lombardo described the shooting as a “lone wolf” attack and there was no information about Paddock’s motives. “We have no idea what his belief system was,” he said.

A woman thought to have been travelling with the gunman before the attack, Marilou Danley, has now been located outside the country, Sherriff Lombardo said.

A police statement said the shooting began at 22:08 local time on Sunday (05:08 GMT on Monday). Paddock came from Mesquite, some 60 miles (100 km) north-east of Las Vegas, and had resided in the hotel since 28 September.

Police say at least 200 people were injured. Fire officials said 406 people were taken to hospital. 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. People sheltered in hotels, restaurants and at Las Vegas McCarran airport.

A witness, Mike Thompson from London, said 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.