At least 35 people have been killed in a string of tornadoes that ripped across large swath of the central and southern United States since Sunday, CNN reported.

At least 17 people were killed in Mississippi, Alabama and Tennessee on Monday, in addition to 18 others reported in Arkansas, Oklahoma and Iowa from storms on the previous day.

Search and rescue efforts were still underway in Louisville, Mississippi, where a tornado the day before flattened a day care center, said Robert Latham of the Mississippi Emergency Management Agency.

Meanwhile, the storm that ravaged Mississippi and Alabama overnight was entering parts of Florida, Georgia and the Carolinas, according to the National Weather Service (NWS).

In Alabama, about 90,000 homes and businesses were without electricity Tuesday afternoon, according to Brian Corbett of the Alabama Emergency Management Agency.

Entergy Mississippi also said about 10,000 of its customers remained in the dark around Jackson, Mississippi.

By Tuesday night, the NWS has downgraded the threat of severe storms that could produce large tornado tracks in eastern United States, but some storm risks remain for parts of the South and East Coast.