Severe storms and tornadoes have ripped across the US state of Tennessee, shredding at least 40 buildings, causing severe damage in the state capital and killing at least 19 people, officials said on Tuesday.

The storms hit in the early hours of Tuesday morning, blowing down walls and roofs, snapping power lines and bring down trees.

The death toll jumped to 19 on Tuesday, Tennessee Emergency Management Spokeswoman Maggie Hannan said, after police and fire crews spent hours pulling survivors and bodies from wrecked buildings.

"Last night was a reminder about how fragile life is," Nashville Mayor John Cooper said at a Tuesday morning news conference.

Schools, courts and transit lines were closed, and some damaged polling stations were moved only hours before Super Tuesday primary voting was set to begin.

Caught a twister passing through East Nashville on my nest cam! 🌪@DanielleBreezy pic.twitter.com/5XMdVTIFYh — Ashley Matte (@AshleyMatte) March 3, 2020

'Stay home if you can'

One tornado near downtown Nashville, the state capital, reportedly stayed on the ground as it travelled about 16 kilometres (10 miles) east of the city. Other areas in the capital region reporting extensive damage.

Below is an estimated illustration of the tornado damage path through the city limits: pic.twitter.com/GUwbK8dc11 — Mt. Juliet Police (@MtJulietPolice) March 3, 2020

“Our community has been impacted significantly," the Mount Juliet Police Department tweeted, adding that multiple homes were damaged and multiple injuries were reported. "We continue to search for injured. Stay home if you can."

Police officers and fire crews were also responding to about 40 building collapses around the city, Metro Nashville police said.

Meanwhile, John C Tune Airport, Nashville International's sister airport in West Nashville, “sustained significant damage due to severe weather", spokeswoman Kim Gerlock said in a statement early on Tuesday morning, adding no injuries were reported.

People walk past buildings damaged by storms in Nashville [Mark Humphrey/The Associated Press]

She asked that the public avoid the airport until further notice and said that the Airport Authority has activated its Emergency Operations Center to coordinate the response.

A video posted online from east Nashville showed what appeared to be a well-defined tornado moving quickly across the city. Lightning repeatedly flashed while much of the city was in the dark. The whir of the wind could be heard gusting after the tornado moved out of sight.

East Nashville took a huge hit last night, this is terrifying. pic.twitter.com/bXmkOl14QF — Reama (@palidose) March 3, 2020

Other images posted on social media showed extensive damage to buildings, mangled wires on downed power lines and structures reduced to rubble. One photo showed a white vinyl fence that had fallen on a car. Another showed the roof and walls gone from a building that still had what appeared to be boxes stacked on shelves.

Among the collapsed buildings was a popular music venue that had just held an election rally for presidential candidate Bernie Sanders. The crowd left shortly before the twister struck the Basement East Nashville, the Tennessean reported.

Super Tuesday affected

The disaster impacted primary voting in Tennessee, one of 14 Super Tuesday states. Some polling sites in Nashville were moved, and polls in Davidson and Wilson counties were opening an hour late but still closing at 8pm local time (02:00 GMT on Wednesday), Secretary of State Tre Hargett announced.

Jeff Roberts of the Elections Commission said in a statement on early Tuesday that information about damage to polling stations is being collected as polls open for Super Tuesday.

Any voter in Davidson County whose assigned precinct has been impacted may vote at the Election Commission Offices, the statement said.

Power outages early on Tuesday morning affected more than 44,000 customers, with Nashville Electric tweeting that four of its substations were damaged in the tornado.

Bricks from a collapsed wall of a restaurant litter the ground after a tornado touched down in downtown Nashville [Alex Carlson/The Associated Press]

Metro Nashville Public Schools district said its schools would be closed on Tuesday because of the tornado damage. Wilson County, just east of metropolitan Nashville will close schools for the rest of the week.

However, election polling sites at schools were expected to remain open, as well as district offices, according to tweets from its official account.