Three girls among Oklahoma tornado dead; clean-up underway

She spoke to several whose homes were struck, including a man who said he was asleep on his sofa with his dog when the tornado hit, depositing them unhurt in the backyard.

A tornado that struck Woodward in April 1947 still ranks as the deadliest in Oklahoma history, with 116 people killed, according to the National Weather Service.

In tiny Thurman, Iowa, population 250, some 75 percent to 90 percent of the town's buildings and homes were damaged or destroyed by the storm, Fremont County Emergency Management Coordinator Mike Crecelius said. Only minor injuries were reported.

Ninety-eight tornadoes

The US tornado season started early this year, with twisters already blamed for 62 deaths in 2012 in the Midwest and South, raising concerns that this year would be a repeat of 2011, the deadliest tornado year in nearly a century.

Some 550 people died in tornadoes last year, including 316 killed in an April outbreak in five Southern states, and 161 people in Joplin, Missouri, the following month.

The National Storm Prediction Center had an unofficial count of 98 tornadoes in Nebraska, Iowa, Kansas and Oklahoma, starting Saturday morning and going until early Sunday.

No deaths or serious injuries were reported in Kansas, but about 11,000 people were reported without power, most of them around Wichita, Sharon Watson, a spokesperson for the state's National Guard and emergency services, said in a statement.

The storm damaged a hangar at McConnell Air Force Base in Wichita and destroyed several homes around the area, authorities said.

Populated neighbourhoods

Storm chaser Brandon Redmond, a meteorologist with the Severe Weather Alert Team, said the twister passed over his vehicle and lifted it 2 feet (60 cm) off the ground in an industrial area south of Wichita, the state's second-largest metropolitan area after the Kansas City metro area.

"The tornado literally formed over our vehicle," he told Reuters. "I've never been that scared in my life. ... We had power flashes all around us and debris circulating all around the vehicle, sheet metal, parts of a roof, plywood."