President Joe Biden early Sunday issued an Emergency Declaration for Mississippi, making federal funding available to Carroll, Humphreys, Monroe and Sharkey counties, the areas hardest hit Friday night by a deadly tornado that ripped through the Mississippi Delta, one of the poorest regions of the U.S.

CBS News has confirmed at least 26 people were killed in Mississippi and Alabama as the massive storm ripped through several towns on its hour-long path. Dozens others were injured

Search and recovery crews on Sunday resumed the daunting task of digging through the debris of flattened and battered homes, commercial buildings and municipal offices after hundreds of people were displaced.

Homeland Security Secretary Alejandro Mayorkas and FEMA Administrator Deanne Criswell are scheduled to travel to Mississippi Sunday to evaluate the damage.  

FEMA Coordinating Officer John Boyle has been appointed to oversee federal recovery operations. Following Biden's declaration, federal funding can be used for recovery efforts including temporary housing, home repairs, loans covering uninsured property losses and other individual and business programs, the White House said in a statement.

The twister flattened entire blocks, obliterated houses, ripped a steeple off a church and toppled a municipal water tower. Even with recovery just starting, the National Weather Service warned of a risk of more severe weather Sunday — including high winds, large hail and possible tornadoes — in eastern Louisiana, south central Mississippi and south central Alabama.

traversed at least 170 miles (274 kilometers), said Lance Perrilloux, a meteorologist with the National Weather Service's Jackson, Mississippi, office.

"That's rare — very, very rare," he said, attributing the long path to widespread atmospheric instability.

Perrilloux said preliminary findings showed the tornado began its path of destruction just southwest of Rolling Fork before continuing northeast toward the rural communities of Midnight and Silver City and onward toward Tchula, Black Hawk and Winona.

The supercell that produced the deadly twister also appeared to produce tornadoes causing damage in northwest and north-central Alabama, said Brian Squitieri, a severe storms forecaster with the weather service's Storm Prediction Center in Norman, Oklahoma