At least 18 dead after storms rage in US states

Powerful storms have killed at least 18 people, injured hundreds and left a wide trail of destruction across Texas, Oklahoma and Arkansas after obliterating homes and destroying a truck stop where dozens sought shelter in a rest room during the latest deadly weather to strike the central US.

The storms inflicted their worst damage in a region spanning from north of Dallas to the northwest corner of Arkansas, and the system threatened to bring more violent weather to other parts of the midwest.

By Monday, forecasters said, the greatest risk would shift to the east, covering a broad swathe of the country from Alabama to near New York City.

Kentucky Governor Andy Beshear declared a state of emergency early on Monday, citing "multiple reports of wind damage and tornadoes".

Seven deaths were reported in Cooke County, Texas, near the Oklahoma border, where a tornado on Saturday night ploughed through a rural area near a mobile home park, Texas Governor Greg Abbott told reporters.

A man looks at a damaged car after a tornado hit in Valley View, Texas
The Valley View area in Texas was among the hardest hit, with winds reaching almost 220km/h. (AP PHOTO)

The dead included two children, aged two and five.

Three family members were found dead in one home, according to the county sheriff.

Storms also killed two people and destroyed houses in Oklahoma, where the injured included guests at an outdoor wedding, eight people in Arkansas and one person in Kentucky.

Tens of thousands of residents were without power across the region.

In Texas, about 100 people were injured and more than 200 homes and structures destroyed, Abbott said, sitting in front of a ravaged truck stop near the small community of Valley View.

The area was among the hardest hit, with winds reaching an estimated 217km/h, officials said.

"The hopes and dreams of Texas families and small businesses have literally been crushed by storm after storm," said Abbott, whose state has seen successive bouts of severe weather.

Hugo Parra said he rode out the storm with 40 to 50 people in the bathroom of the truck stop.

The storm sheared the roof and walls off the building, mangling metal beams and leaving battered cars in the car park.

"A firefighter came to check on us and he said, 'You're very lucky,'" Parra said, adding "the wind tried to rip us out of the bathrooms".

Eight people died statewide in Arkansas, officials said, and in Oklahoma, two people died in Mayes County, east of Tulsa.

In Kentucky, a man was killed Sunday in Louisville when a tree fell on him.

The destruction continued a grim month of deadly severe weather in the nation's midsection.

Tornadoes in Iowa last week left at least five people dead and dozens injured.

The deadly twisters have spawned during a historically bad season for tornadoes, at a time when climate change contributes to the severity of storms around the world.

Harold Brooks, a senior scientist at the National Severe Storms Laboratory in Norman, Oklahoma, said a persistent pattern of warm, moist air was to blame for the string of tornadoes during the past two months.