A powerful tornado have reportedly swept through the US Midwest, destroying buildings and overturning vehicles killing at least six people in the states of Illinois, Indiana and Kentucky.

A number of people are said to be trapped inside buildings and it is feared that several hundred people may have been injured in the fast-moving storms.

According to reports, forecasters said people in 10 states had been at risk. Hailstones the size of tennis balls have been reported.

“Pay attention to all weather alerts and stay home and inside if possible” Pat Quinn, Illinois governor said.

The storm was so fast-moving - with winds of up to 111km/h (68mph) - that weather services issued warnings for people not to wait until they saw the weather change.  It is continuing its way east.

November is ordinarily one of the quietest months in the tornado calendar, meaning these storms are unusually destructive for this time of year, analyst said.