US President Joe Biden declared an emergency and ordered federal aid to Mississippi on Sunday morning to support recovery efforts.

With at least 26 people dead in Mississippi, tornadoes that ravaged parts of the Deep South overnight were the deadliest in the state in more than a decade, according to National Weather Service (NWS) records.

By comparison, 31 people died in Mississippi in April 2011 during tornadoes that tore through several states, mostly in the southeastern United States, NWS meteorologist Chris Outler said Saturday. Alabama was hit hardest during that so-called “super outbreak” of hundreds of twisters that killed more than 320 people and caused an estimated $12bn in damage.

Just a month later, another deadly twister ripped through Joplin, Missouri, killing 158 people. Outler called 2011 “the headline year for tornadoes for the last 20 years or so”.

The sheriff’s office in Morgan County, Alabama reported one storm-related death on Saturday, bringing the overall total during overnight storms to at least 26.