On Friday night, tornadoes ripped through the US state of Mississippi, killing at least 23 people.
More people are believed to be trapped beneath the ruins of destroyed buildings.
Twisters wreaked havoc on several rural towns, destroying trees and power lines and causing tens of thousands of power outages.
Several other southern states are also bracing for severe weather.
In several areas of the state, golf-ball-sized hail and heavy rain were reported.
Residents of Rolling Fork, a small town in western Mississippi, reported that a tornado blew out the back windows of their homes. The damage in the area is said to be particularly severe.
Brandy Showah, a local resident, told CNN: “This is the first time I’ve seen anything like it… This was a fantastic small town, and it’s now gone.”
Cornel Knight told the Associated Press that he, his wife and their three-year-old daughter were at a relative’s home in Rolling Fork and that it was “eerily quiet” just before the tornado struck. The sky was dark, he said, but “you could see the direction from every transformer that blew.”
He claimed that the tornado hit another relative’s home, where a wall collapsed, trapping several people inside.
Other people were trapped in rubble, and some law enforcement units have gone missing in Sharkey County.
Concerned about the strength of a tornado approaching Amery, one local weather forecaster briefly paused his TV forecast to pray for the town’s residents.
Tate Reeves, the governor of Mississippi, said on Twitter that search and rescue teams were providing medical assistance to those affected.
“Many people in the Mississippi Delta need your prayers and God’s protection tonight. Keep an eye on weather reports and be cautious throughout the night, Mississippi! “, wrote Mr Reeves.