At least 50 people have been killed and more than 200 injured after at least one gunman opened fired on concert-goers on the popular Las Vegas Strip in the US state of Nevada.
The mass shooting took place late on Sunday outside a building at the Mandalay Bay Resort and Casino during the Route 91 country festival.
According to the Las Vegas police, the shooter fired into the crowd from the 32nd floor of the Mandalay Bay hotel.
The suspected attacker was later killed in a shoot-out with police, officials said.
Cole Watson, who was at the concert with his wife and kids, said “at first it sounded like someone was setting off a whole lot of fire crackers”.
He said when they “realised it was gunfire and everybody started running”.
“The scene was insane – it was absolute chaos,” Watson told Al Jazeera by telephone.
Wade Millward, a journalist with the Las Vegas Review-Journal, told Al Jazeera that the attack tooke place while country-music star Jason Aldean was performing.
“Witnesses told me they heard a sound like fireworks going off,” he said.
“Aldean played on for about thirty seconds before it dawned on everyone that this was not fireworks. Then people hit the ground and people ran.”
Watson said he saw several injured people when he and his family ran from the scene of the attack.
He added that security showed up “almost immediately”.
Videos posted on social media show the crowd ducking for cover as multiple shots can be heard. Watson said he and his family immediately went to a hotel, where he and his family were staying.
“We are on lockdown now and police is going door to door checking on people,” he said.
The Las Vegas Review-Journal’s Millward told Al Jazeera the lobby of one of the hospitals where victims were taken was packed with friends and family.
“I’ve seen people wearing bloody clothing and there is discarded bloody clothing outside.”
“There are still people walking by with blood on their shirts. There is police everywhere and there are two helicopters flying overhead.”
During a press conference, Clark County Sheriff Joseph Lombardo said that at least 50 people had been killed and more 200 were injured, but added that the precise number of victims could not be given.
Two on-duty police officers were shot, one of them is still in critical condition, Lombardo said.
He also said the suspected shooter, an unnamed Las Vegas resident, was killed in a shootout with police in the hotel hotel room where he was shot.
Lombardo added that police are still looking for a possible accomplice, who is wanted for questioning.
So far in 2017, the watchdog group Gun Violence Archive has documented 273 mass shootings in the US.
The group also recorded 11,621 gun-related deaths and 23,433 firearm-related injuries during that period.
The Mandalay Bay attack comes just weeks after Spencer Hight carried out a mass shooting during a gathering at his estranged wife’s home in Plano, Texas. The assailant killed eight people and was later shot dead by police. (Al Jazeera News)