Searches to resume after tornado kills at least 23

WASHINGTON -- Rescuers prepared on Monday to tear through the rubble of mobile homes and houses in search of survivors of a powerful tornado that rampaged through the southern US state of Alabama and killed at least 23 people.

The tornado uprooted trees and causing "catastrophic" damage to buildings and roads, Lee County Sheriff Jay Jones said.

"Unfortunately, I feel that number may rise yet again but that's going to depend on our search efforts," he told a news conference.

Drones flying overheard equipped with heat-seeking devices had scanned the area for survivors, but the dangerous conditions halted the search late on Sunday, Jones said.

Emergency workers faced a grim night of pulling the dead and injured from the wreckage of homes and businesses in the county that includes Alabama's largest city of Auburn.

"The challenge is the sheer volume of the debris where all the homes were located," Jones said. "It's the most I've seen that I can recall."

Storms, including at least one apparent tornado, uprooted trees and destroyed homes in the neighboring state of Georgia, initially knocking out power to 21,000 customers, said Georgia Power spokeswoman Meredith Stone.

On Twitter, US President Donald Trump urged residents of Alabama and other areas affected by the storms to be "careful and safe".

"Tornadoes and storms were truly violent and more could be coming," Trump wrote. "To the families and friends of the victims, and to the injured, God bless you all!"

Severe weather unleashed one of many possible tornadoes that threatened the southern United States on Sunday afternoon. Tornado warnings and watches were in effect for parts of Georgia and Alabama through Sunday evening.

Video footage from the small community of Beauregard in Lee County, Alabama, showed homes reduced to piles of wreckage, felled trees, and debris from blasted buildings scattered across roads. Alabama Governor Kay Ivey warned on Twitter that more severe weather might be on the way.

"Our hearts go out to those who lost their lives in the storms that hit Lee County today," Ivey wrote. "Praying for their families& everyone whose homes or businesses were affected."

The National Weather Service office in Birmingham, Alabama, said it was sending three survey teams out on Monday to assess damage in Autauga, Macon, Lee and Barbour counties.