Four dead in US tornadoes

Four people were killed in an outbreak of violent weather in Oklahoma today, as tornadoes whipped across the state, tossing cars off highways and flipping mobile homes.

Oklahoma Department of Emergency management spokesman Jerry Lojka said one person was killed in Oklahoma City and three were killed in Tecumseh, which is about 72km southeast. The agency did not have any additional details, including how the people died.

Officials reported that at least seven people were injured in the daylong onslaught, which forecasters had predicted since last week. The storms were part of a violent weather system that also spawned twisters in Kansas and elsewhere in Oklahoma.

Power was out to at least 31,000 homes and business in Oklahoma. Authorities closed two cross-country interstate highways because wrecked vehicles blocked the roads.

"The kids and I got in the closet and prayed," said Jamie Keyes, of Norman, about 20km south of Oklahoma City. "I heard a hiss. It was like something was whistling very loud," she said. "We're all very fortunate."

Interstate 35, which runs from Mexico to Minnesota, was closed for a time at the Kansas-Oklahoma border because overturned tractor-trailers blocked all lanes. At Moore, near Oklahoma City, trucks were overturned in the median but the road remained open.

Oklahoma City and its suburbs saw three storms develop just to the west and each caused damage as they moved across an area home to 1.2 million people.

The northern storm caused property damage near Edmond; two storms to the south turned into killers - the one fatality near the truck stop and the three at Tecumseh, on the metro area's eastern edge.

"We've had a very strange event: multiple tornadic portions with this event as it came through," said David Barnes, the emergency management director for Oklahoma County. "We have multiple vehicles overturned, a housing addition has had multiple homes destroyed."

The Storm Prediction Center at Norman had predicted the outbreak, saying the atmosphere had the right mix of winds, heat and moisture. One twister touched down just east of the centre's building on the University of Oklahoma campus.

- AP