People view damage along Woodland Street after a Tornado touched down in Nashville on Tuesday. Reuters

At least 19 people were killed early on Tuesday after powerful tornadoes ripped through Nashville and other parts of Tennessee, flattening buildings and leaving tens of thousands of people without power, authorities said.

The death toll, provided by the Tennessee Emergency Management Agency, may rise given the number of people who remain missing statewide, Governor William Lee said at a news briefing.

Rescue teams were going door to door, searching damaged structures for trapped or injured individuals, the Nashville Fire Department said.

At least 30 people were injured in Nashville, the state capital, and least 48 buildings were destroyed, with many more damaged, Fire Department Director Chief William Swann said.

A man views damage in an alley behind Woodland Street in Nashville on Tuesday. Reuters

Tennessee is one 14 states that will be holding primary elections on Super Tuesday. Despite the widespread destruction, polling sites at schools and elsewhere will be open for voting unless otherwise noted, officials said.

"We want people to exercise their rights and get out there and vote," Lee said.

Lightning that accompanied the tornado lit up the darkened sky as the storm rumbled through central Nashville, video posted on Twitter showed.

At daybreak, video footage on local television revealed leveled houses and crumbled businesses in Nashville, a city of 691,000.

Debris covers a car near after a tornado touched down at Donelson Christian Academy in Nashville on Tuesday. Reuters

Crushed vehicles, piles of debris and power lines snapped in two were strewn about, and rescue vehicles blocked streets as residents carried their belongings away from their destroyed homes.

The police department in the Mt. Juliet suburb east of Nashville reported multiple homes damaged and people injured.

"This was obviously a very strong tornado. There are multiple homes damaged, multiple people injured, multiple people still trapped," Mt. Juliet Police Captain Tyler Chandler said in a video posted on Facebook. "We need your help. And that means if you can stay at your house, please stay home."

Schools, district offices and courts will close on Tuesday due to the tornado damage throughout Nashville, apart from the public buildings set to be used for polling.

Associated Press