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