Tornadoes brought Christmas Eve havoc to the southern US killing at least 14 people and damaging or destroying dozens of homes.

Instead of doing some last-minute shopping or wrapping gifts, families were taking stock of their losses after an unusual outbreak of December violent weather.

In Benton County, Mississippi, four people - including a married couple and two neighbours on the same street - were confirmed dead and their homes destroyed.

"Santa brought us a good one, didn't he?" Bobby Watkins said as he and his wife took a walk amid the destruction.

"I may have lost some stuff, but I got my life."

Unseasonably warm weather on Wednesday helped spawn twisters from Arkansas to Michigan.

The line of spring-like storms continued marching east on Christmas Eve, dumping torrential rain that flooded roads in Alabama and caused a mudslide in the mountains of Georgia.

Authorities confirmed seven deaths in Mississippi, including a seven-year-old boy who was in a car that was hit by a storm. Six more died in Tennessee. One person was killed in Arkansas.

Dozens more were injured, some seriously, said Greg Flynn, spokesman for the Mississippi Emergency Management Agency.

Search teams combed damaged homes and businesses for people still missing, including at least one man in hard-hit Benton County. The hunt was made complicated because so many had left for the holidays.

"Until they know for sure where those folks are, they're going to keep looking, because we've had in some cases houses levelled, and they're just not there anymore," Mr Flynn said.

In Benton County, relatives helped Daisy and Charles Johnson clean up after the storm flattened their house. They carried some of the couple's belongings past a Santa Claus figure on a table.

Mrs Johnson, 68, said she and her husband rushed along with other relatives to their storm shelter across the street from the house after they heard a twister was heading their way.

"We looked straight west of us and there it was. It was yellow and it was roaring, lightning just continually, and it was making a terrible noise," she said. "I never want to hear that again for as long as I live."

Peak tornado season in the south is in the spring, but such storms can happen at any time. Exactly a year ago, twisters hit Mississippi, killing five people and injuring dozens.

Glenda Hunt, 69, was cooking chicken on Wednesday night at her Benton County home, where Christmas Eve lunch is a family tradition, when her daughter called to warn her of the approaching storm.

She and her husband ducked into their storm shelter and wrestled the door shut against the wind's powerful suction. She started praying when she heard sheet metal hitting trees.

On Thursday, heavy farm equipment and corn were strewn across the couple's property. Their house sustained heavy structural damage but was still standing.

"We're OK and that's all that matters," she said. "But the Lord did save my furniture."

In Linden, Tennessee, Tony Goodwin ducked into a storm shelter with seven others as the storm passed. He emerged to find his house had been knocked off its foundation and down the hill.

He managed to climb inside and fetch some Christmas gifts that had been under his tree. His neighbours were not so fortunate. Two people in one home were killed.

"It makes you thankful to be alive with your family," he said. "It's what Christmas is all about."

Chris Shupiery grabbed his Santa hat along with a chain saw as he set out to help clean up. He cut up fallen trees not far from Mr Goodwin's home.

"This was just the right thing to do, come help a family in need," Mr Shupiery said.

"Suit up, try to cheer people up and try to make them feel a little better with Christmas coming around."