At least 18 people have been killed by tornadoes and storms that hit large areas of the United States, particularly in the south, destroying many buildings, as the northeast braced for possible strong thunderstorms on Saturday.

The Associated Press said tornadoes swept through at least seven states overnight, destroying homes and businesses, and storms triggered wildfires.

The agency reported that the death toll includes 7 people who died in one county in the southeastern state of Tennessee.

Tens of thousands of people were without power as storms swept across large swathes of some 85 million people.

In southern Arkansas, at least five people have been killed, Gov. Sarah Huckabee said at a news conference.

Huckabee said she discussed the situation with US President Joe Biden after declaring a state of emergency in the state and hiring about 100 National Guard personnel.

In the state capital of Little Rock, residents woke up on Saturday to scenes of overturned cars, huge trees, uprooted phone poles and destroyed homes.

Little Rock Mayor Frank Scott told reporters: "We know that many people have been displaced and are seeking refuge."

The tornado left widespread destruction in Wayne Township, Arkansas (Reuters)

Lara Farrar, a journalist for a local economic newspaper, told AFP she was shocked by the scale of the destruction at Little Rock.

"The roofs of some houses have been completely destroyed," she said, posting photos of destroyed houses, partially collapsed walls and trees on the ground. "The neighborhood is completely destroyed," she said, pointing to rubble stretching for about 500 metres.

The northeastern town of Wayne is "almost divided by east-west damage," Mayor Jennifer Hobbs told CNN.

In the northern United States, in the small town of Belvedere west of Chicago, Illinois, part of the roof of a concert hall collapsed after a severe storm passed while the audience was watching a performance by a metal band, local media reported.

The Belvedere fire chief said one person died and 28 others were injured, including 5 who were taken to hospital with serious injuries. Local media reported that more than 20 ambulances arrived at the site.

Television footage showed evacuations of wounded people on stretchers, and images on social media showed rubble and a large hole in the ceiling.

⚠️BREAKING: Part of the roof at the Apollo Theatre in Belvidere, Illinois has just collapsed during Morbid Angel's concert.
– possibly weather-related, as a tornado moved through area
– Belvidere is located in Boone County, about 72 miles from Chicago.#ApolloTheatre

— Disidente Incontrolable (@Pjt432) April 1, 2023

In the northern state of Indiana, three people died in a storm in Sullivan County, US media quoted authorities as saying.

Photos posted on Twitter showed phone poles, collapsed houses and rubble falling on roads.

Power Outage reported that at least 200,<> homes were without power on Saturday in Indiana, Arkansas and Illinois.

The National Weather Service warned of strong winds and storms that could hit the northeast on Saturday, especially Ohio.

Tornadoes are a difficult phenomenon to predict and are frequent in the United States, especially in the center and south of the country.

A week ago, a tornado hit Mississippi, leaving 25 people dead and extensive property damage. President Joe Biden inspected the site on Friday.

In December 2021, about 80 people died after tornadoes hit Kentucky.