(Photo/CGTN)

BEIJING - President Xi Jinping on Monday sent a condolence message to his US counterpart, Donald Trump, over the mass shooting in Las Vegas in the US state of Nevada.

The shooting caused heavy casualties, Xi said as he extended deep sympathy to the US government and people, profound condolences to the victims, and sincere solicitude to those wounded.

The Chinese president also wished a quick recovery of the injured.

A gunman opened fire on a country music concert in Las Vegas in the US state of Nevada on Sunday night, killing at least 59 people and injuring more than 500 others in the deadliest mass shooting in modern US history, police said on Monday.

More than 22,000 people were attending the outdoor music festival when the gunman rained bullets from a high-floor hotel room of the Mandalay Bay Hotel and Casino on the Las Vegas Strip, the police said.

The Islamic State group claimed responsibility for the attack, saying the shooter had converted to Islam months ago, Reuters reported. The group provided no evidence.

The death toll, which police emphasized was preliminary, would make the attack the deadliest mass shooting in modern US history, eclipsing last year's massacre of 49 people at an Orlando nightclub.

Thousands of panicked people fled, in some cases trampling one another as law enforcement officers scrambled to locate and stop the gunman. Shocked concertgoers, some with blood on their clothes, wandered the streets.

Police identified the gunman as area resident Stephen Paddock, 64, but said they had no immediate information about his motive.

[RELATED:  Profile of shooter behind Las Vegas massacre]

He was not believed to be connected to any militant group, Clark County Sheriff Joseph Lombardo told reporters. "We have no idea what his belief system was," Lombardo said. "Right now, we believe he was the sole aggressor. We've located numerous firearms within the room that he occupied."

Las Vegas police said they no longer think Marilou Danley, 62, who they were seeking, was involved in the shooting. Police initially said they were looking for the woman, who may have been the roommate of the shooter.

The dead included one off-duty police officer and at least one other officer was critically injured. Police warned the death toll may rise.

Thousands of fans were attending the concert next to the Mandalay Bay that was part of Route 91, a three-day country music festival.

Video of the attack showed panicked crowds fleeing as sustained rapid gunfire ripped through the area. Witnesses told how the gunman opened fire with an initial burst and then appeared to reload as he continued his spree.

Luo Xianlin, a Chinese tourist, said that he was walking on the street when the shooting happened, and ran into Caesars Palace Hotel with a crowd of frantic people. "I didn't hear any sound of opening fire, but I ran with other people. Some stayed in the lobby. My four Chinese colleagues and I hid in a room with seven Guatemalans and two Germans for four hours," he said.

Steve Smith, a 45-year-old visitor from Phoenix, Arizona, said the gunfire went on for an extended period.

"Probably 100 shots at a time. It would sound like it was reloading and then it would go again," he said. "People were shot and trying to get out. A lot of people were shot."

Online travel agency Ctrip told China Daily that eight of its Chinese clients had been trapped in the hotel where the shooting originated. All were safe and left the blockaded hotel with the help of police on Monday. They were moved to another hotel in the city.

US President Donald Trump offered his condolences to victims in a Twitter post early on Monday. "My warmest condolences and sympathies to the victims and families of the terrible Las Vegas shooting. God bless you!" Trump said.

AFP—Reuters—AP—Xinhua

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