At least 13 people have been killed as tornadoes tore across three US states, destroying homes in minutes and leaving hundreds of thousands without power.

Four people were killed in Arkansas, two in Oklahoma and seven in Texas. Scores more were injured.

Sheriff Ray Sappington of Cook County, Texas, said the death toll there included two children aged 2 and 5. He added the number of casualties was expected to rise.

Footage showed a petrol station in the county almost completely destroyed, with twisted metal littered over damaged vehicles.

“We’re still in search and rescue mode right now. I hope we can still find survivors,” he told US media early on Sunday.

“It’s just a trail of debris left. Sadly we think that number is probably going to go up. The devastation is pretty severe.”

The twisters overturned lorries, shut a highway near Dallas and left tens of thousands of people without power throughout the region.

Frank Soltysiak, who lives in a mobile home park in north Texas, said that his home was destroyed within minutes when the storm passed through.

Mr Soltysiak had been in a nearby restaurant when the owner drove by “honking his horn, telling everybody to get out”, he told told CBS News, the BBC’s US partner.

He grabbed his dog Sampson and took shelter in the walk-in refrigerator of the restaurant.

“That was the most secure structure you could have gone to. And I come out, and everything is destroyed,” he said.

“In a matter of two minutes, it’s gone, everything is gone.”

The storms in Texas overlapped with record-breaking heat in some parts of the state, with residents receiving triple-digit temperature warnings over the Memorial Day holiday weekend.

In Oklahoma, two people were killed in Mayes County and six others injured, the local emergency management authority told the BBC.

Arkansas officials said a 26-year-old woman was found dead outside a destroyed home in Olvey, while another of the four deaths in the state was reported in Benton County. The state also reported multiple people injured.

Police officials in the city of Rogers, Arkansas, said they had rescued several people who were trapped after a tornado downed trees and power lines, and damaged gas supply lines.

By Sunday afternoon, the storm had begun moving east, according to the National Weather Service, which warned of severe wind and hail for those in its path.

Some 470,000 people were without power in states stretching from Texas to Kansas, Missouri, Arkansas, Tennessee, and Kentucky, according to the website Poweroutage.us.

As far north as Indiana, the start of the Indianapolis 500 was delayed on Sunday due to storms in the area, with fans asked to exit their seats and seek shelter.

A crowd of 125,000 was expected for the race.

The latest twisters follow another powerful tornado which tore through a rural Iowa town and killed four people earlier in May.

Government forecasters have also described this summer as a possibly “extraordinary” 2024 Atlantic hurricane season, beginning next month.