The storms late Thursday and early Friday ripped off roofs and toppled train cars near Kansas City, Mo.; pelted parts of Oklahoma with hail; and knocked over tents at a popular open-air market in east Texas. Severe thunderstorms were moving into Kentucky and could make for a wet Kentucky Derby today.

Greg Carbin, a meteorologist for the national Storm Prediction Center in Norman, Okla., said as many as 25 tornadoes may have cut through stretches of Oklahoma, Arkansas, eastern Kansas and western Missouri.

Five of those killed were in two north-central Arkansas counties, Conway and Van Buren, that also saw fatalities from a devastating tornado Feb. 5. Gov. Mike Beebe declared those counties and five others disaster areas.

"This year it just seems like we're getting pounded," Van Buren County Sheriff Scott Bradley said.

He said a man, a woman and a preschool-age child died when the storm hit their house just south of Bee Branch.

"There wasn't anything left," Bradley said. "It was demolished."

Another child who lived at the home had already left for school, escaping injury.

A father and son died in Conway County when a possible tornado hit their mobile home. A twister demolished a chicken farm in Center Springs, leaving thousands of dead birds on the ground.

Near the Oklahoma line in a working-class neighborhood of Siloam Springs, a 15-year-old girl died in the early morning when apparent straight-line winds toppled a tree into her family's mobile home. She and her 10-year-old brother were sleeping in bunk beds; the boy survived with minor injuries.

The seventh death was reported in Pulaski County, south of Little Rock.

More than a dozen injuries were reported, and about 350 homes were damaged or destroyed in several Arkansas counties.