At least 15 people have been killed as tornadoes and storms tore across central areas of the US, destroying homes and cutting power to hundreds of thousands.

Seven people were killed in northern Texas, five in Arkansas, two in Oklahoma and one in Kentucky. Scores more were injured, and almost 500,000 were without electricity across several states on Sunday.

Sheriff Ray Sappington of Cook County, Texas, said the death toll there included two children aged 2 and 5 and three members of the same family.

"It's just a trail of debris left," said the sheriff of Valley View area, which was among those hardest hit by a powerful tornado. "The devastation is pretty severe."

Footage from the county showed a petrol station and rest stop almost completely destroyed, with twisted metal littered over damaged vehicles.

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

Lightning, thunder and heavy rain meanwhile forced the evacuation of around 125,000 spectators as Sunday's Indianapolis 500 race was delayed by four hours.

Everything gone in two minutes

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

Texas Lieutenant Governor Dan Patrick said that state emergency response units were activated to respond to the tornado.

"Please pray for these families," he said of those whose loved ones were killed. "Their loss is unfathomable."

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.

In Kentucky, Louisville mayor Craig Greenburg confirmed on social media that a man was killed by a falling tree during a severe storm on Sunday.

Storms move east

By Sunday afternoon, the storm system 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.

A spokesperson for Kansas' Sedgwick County, which includes Wichita, told CBS News that emergency services were dealing with downed trees and power lines from a storm, with about 8,000 customers without power.

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.