The mass shooting – described as the worst in US history – saw 64-year-old Stephen Paddock use at least 42 guns, explosives and several thousand rounds of ammo.

Officers recovered 19 firearms from Paddock’s home in Mesquite, Nevada, hours after discovering 23 guns in the Mandalay Bay hotel in Las Vegas, from where he killed at least 59 concertgoers.

Swat teams found the retired accountant dead in his room on the 32nd floor of the hotel.

The Foreign Office (FCO) said it is in contact with the local authorities and urgently seeking further information following a shooting.

“You should avoid the area and follow the advice of the local security authorities,” it said on its website.

“Road closures are in place in the area. A number of flights have been diverted from Las Vegas McCarran International airport. You should check with your airline before travelling.”

The Las Vegas Metropolitan Police Department has opened a dedicated telephone line for anyone concerned about specific individuals in the area around the Mandalay Bay Hotel (+1 866 535 5654).

Foreign Secretary Boris Johnson said: “I am horrified by the awful attack at a music festival in Las Vegas this morning. The United Kingdom stands with the American people against this indiscriminate violence. My thoughts are with all those caught up in it.

“The FCO is in contact with Las Vegas authorities to establish whether any British people were caught up in the attack and we are ready to help however we can. Any British people in Las Vegas should follow the instructions of local authorities.”