VILONIA (REUTERS) - A ferocious storm system threatened tens of millions of people across the US Southeast on Monday, a day after it spawned a series of tornadoes that killed 16 people, injured more than 100 and tossed cars around like toys in Arkansas and Oklahoma.
Rescue workers, volunteers and victims have been sifting through the rubble in the hardest-hit state of Arkansas, looking for survivors in central Faulkner County where a tornado reduced homes to splinters, snapped power lines and mangled countless trees.
The National Weather Service said there was a tornado risk for Mississippi, Alabama and western Georgia as the storm system that produced the twisters headed east toward the Mid-Atlantic states.
Arkansas Governor Mike Beebe said at least 14 people died in the state in the storm authorities said produced the first fatalities of this year's US tornado season. He previously told a news conference 16 had been killed but later said there was a mistake in calculation.
Nine of the victims came from the same street in the town of Vilonia, with a population of about 4,100. A new intermediate school set to open in August was heavily damaged by a tractor trailer blown into its roof.
A steel farm shop anchored to concrete was erased from the landscape. "Everything is just leveled to the ground," Vilonia resident Matt Rothacher said. "It cut a zig-zag right through town."
The White House said President Barack Obama, who has been on a trip abroad, called Beebe to receive an update on the damage and to offer his condolences.
Medical officials reported at least 100 people in Arkansas were injured. "It's so heartbreaking. I've never seen destruction like this before," US Representative Tim Griffin told reporters after touring Vilonia, which was previously hit by a tornado about three years ago. "I saw a Dr. Seuss book in the rubble. I saw a Spider-Man shirt in the rubble. It just breaks your heart."
The National Weather Service said the threat of tornadoes will last for several days as a strong weather system interacts with a large area of instability across the central and southern United States.
"This is a multiday event and today is the second day of significant tornado risk and unfortunately, probably not the last," said Bill Bunting, operations chief at the National Weather Service's Storm Predictions Center in Norman, Oklahoma.
North Carolina Governor Pat McCrory declared a state of emergency for four counties where tornadoes hit on Friday and warned that more rough weather was on the way.
More than 10,000 people were without power in Arkansas on Monday morning, officials said.
The Arkansas National Guard was deployed to sift through the wreckage. Beebe declared a state of disaster for Faulkner and two other counties.
One person was killed in neighboring Oklahoma and another in Iowa, state authorities said.
A tornado in Baxter Springs, Kansas that touched down on Sunday evening destroyed as many as 70 homes and 25 businesses and injured 34 people, of whom nine were hospitalised, state and county officials said.
One person was killed in Kansas, likely due to the same storm system, officials said.