“He [Paddock] was just spraying the crowd, it was relentless, there was no stopping, maybe five or eight seconds to move from cover to cover to try and get out as he reloaded.”

Among those killed were at least two off-duty officers.

Laura Robson, the 23-year-old British tennis player, posted on social media: “I’m OK. We were right there … sounded like fireworks at first then everyone started running. Scary. My friend who was deeper in the crowd has been helping people who were shot. We’re all in shock.”

One survivor, not named, told US television of trying to drag victims under the stage for cover. A friend was shot three times but made it out alive.

The witness said: “My buddy got hit three times. We were diving for the ground. Lots of people got hit. We climbed over a fence and under the stage. One guy ended up dying in my arms; he was bleeding.”

Samantha Evans, 36, a holiday rep from Cardiff, told how she threw herself to the floor to dodge the bullets and watched in horror as a security guard was shot just feet from her.

She said: “At first I thought it was fireworks but then I heard screams as people were being shot. We all ducked down as low as we could, I was on the floor. It went on for 10 minutes but it felt like forever.” Ms Evans had taken her mother, Charley Wilson, to the Las Vegas country music festival as a treat for her 60th birthday. Mrs Wilson was in her mobility scooter along with 30 other disabled people on a raised platform for a better view. “The gunfire sounded really close, we just ducked down and prayed,” Ms Evans said.