Tornadoes² have hit a large swathe of the US Midwest, with forecasters warning of further severe weather.

龙卷风袭击了美国中西部大片地区，更恶劣的天气即将来临。

Storms were reported in Kansas, Iowa, Nebraska and Oklahoma, but no injuries have been reported so far.

The National Weather Service had warned there could be further tornadoes early Sunday morning, with concern they could strike as people slept.

But it said that the chance they would be very strong or long-lived was lower than the previous evening.

Forecasters had warned that the worst of the weather would hit around nightfall.

Officials feared people would not hear warnings as they slept and said that it was more difficult for weather spotters to track the funnel³ clouds overnight⁴.

'House shaking'

One tornado¹ destroyed large parts of the town of Thurman, in Iowa, on Saturday, but there were no major injuries, the NWS said.

"It lasted three to four minutes probably - what seemed like an eternity," one man from Thurman told the broadcaster ABC.

"The next thing I know, the house was shaking and I could feel it lifting and it was over that quick," another man said.

Another tornado caused widespread power outages and other damage in the city of Wichita, Kansas, according to Associated Press.

The roof of a hospital in Creston, southwest of Des Moines, was damaged, but patients and staff were not hurt, AP reported.

Tornado experts had said that storms on Saturday could be a "life-threatening event".

US tornadoes have already killed at least 39 people in 2012.

An outbreak of deadly twisters hit the states of Indiana, Kentucky, Ohio, Georgia and Alabama in early March.

At the start of April the Dallas-Fort Worth area was badly hit, with hundreds of flights being disrupted⁵ but no-one injured or killed.