Tornadoes and storms that somebody been battering the confederate US killed at minimal 128 grouping on Wednesday in Alabama lone, country officials say.
One of the hardest-hit cities was Tuscaloosa, where at slightest 15 fill died when a monumental tornado struck.
With deaths also in Georgia, Tennessee and River, at smallest 172 fill in total know been killed in past life.
States of emergency have been declared in seven states, and federal aid money is being sent to Alabama.
The US National Weather Service has preliminary reports of nearly 300 tornadoes since the storm began on Friday, including more than 130 on Wednesday alone.
One meteorologist described the tornado that devastated Tuscaloosa as possibly the “worst in Alabama’s history”.
The city – home to more than 83,000 residents, and to the University of Alabama – was hit by the huge tornado in the early evening on Wednesday.
“Everybody says it [a tornado] sounds like a train and I started to hear the train,” Tuscaloosa resident Anthony Foote told Reuters news agency.
“I ran and jumped into the tub and the house started shaking. Then glass started shattering.”
By nightfall, the city was dark, with roads impassable, businesses unrecognisable, sirens wailing off and on, and debris littering the streets and pavements, the Associated Press reports.
The city’s hospital said its emergency room had admitted about 100 people, but treated four times that number.
Mayor Walter Maddox told reporters the city faced “massive damage on a scale we have not seen in Tuscaloosa in quite some time”, and said he expected the death toll to rise.
A state of emergency has been declared in Alabama.
Northern and central parts of the state bore the brunt of the latest storms. Eleven people died in Jefferson County, home to Birmingham, Alabama’s largest city.
President Barack Obama said he had spoken to state Governor Robert Bentley and approved his request for emergency assistance, including search and rescue teams.
Mr Obama said on Wednesday night: “We will continue to monitor these severe storms across the country and stand ready to continue to help the people of Alabama and all citizens affected by these storms.”
States of emergency were also declared in Arkansas, Kentucky, Mississippi, Missouri, Tennessee and Oklahoma, following the latest storms and tornadoes.
Mississippi reported 32 deaths on Tuesday and Wednesday – including that of a police officer who shielded his nine-year-old daughter from a falling tree while on a camping holiday. The girl escaped unhurt.
A woman was also killed in eastern Tennessee when trees fell on her trailer home in Chattanooga.
At least 11 people are reported to have been killed in Georgia.
The current storm system is forecast to hit North and South Carolina before making its way further north-east.
Storms have hit states across the southern US for weeks, and another major storm system is forecast to bring heavy rain in the coming days.