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. 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. Live updates on Las Vegas mass shooting Las Vegas shooting - what we know 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 say at least 200 people were injured. Fire officials said 406 people were taken to hospital. 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. What we know about the gunman The fake photos shared after tragedies 'Attack will stun America' By the BBC's James Cook, in Las Vegas This has been a mass shooting which has shocked Las Vegas - it has stunned this city. It is very clear that it will be an event which will stun the USA too, a country in which, regrettably, such mass shootings - even if on a lesser scale - are not uncommon. As to why the gunman may have carried out this attack, there is no indication of motive at this stage. He was said to have had a large arsenal, a huge number of weapons in that hotel room, which police finally stormed using explosives. As to why he would have set himself up there in that way, to do as he did, it is just so difficult to fathom. 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, 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.