Aerial footage reveals destruction of deadly Nashville tornadoes

Aerial footage showing the devastation wreaked by two deadly tornadoes in Nashville in Tennessee has been released.

It comes as more than 20 people have died after the tornadoes struck central Tennessee, including one that ripped across Nashville causing at least 50 buildings to collapse.

Authorities are continuing to search the wreckage for injured people as the storms struck on Tuesday morning as families slept.

Police pleaded with people to stay indoors, at least until they could deal with the dangers of a landscape littered with rubble from walls and roofs, as well as snapped power lines and downed trees.

Schools, courts and transport lines were closed, and four polling stations were moved only hours before Super Tuesday voting was set to begin, forcing voters to wait in long lines at alternative sites.

Bricks from a collapsed wall of the Geist restaurant litter the ground after a tornado touched down in Nashville. Credit: AP

Nashville mayor John Cooper told the Tennessean while visiting an emergency shelter: “A tornado skipped across the county.

“You do have people at the hospital and frankly there have been fatalities.”

The tornado reportedly stayed on the ground into Hermitage, about 10 miles east of the city.

Other areas reporting extensive damage included Mt Juliet and Germantown.

Local police in Mt Juliet tweeted: "Our community has been impacted significantly. We continue to search for injured. Stay home if you can."