Some residents of Washington, Illinois, picked through the remains of their tornado-flattened homes yesterday, recovering what they could a day after a series of twisters pounded the Midwest, killing eight people.

Bits of American flags and insulation from destroyed houses clung to trees that had been stripped of most of their branches and remaining leaves by the Washington twister.

Spawned by a fast-moving storm system, the tornado had winds of up to 320 kilometres per hour.

Six people died in Illinois in storm-related accidents and Michigan officials yesterday reported two new deaths.

Police were keeping residents from returning to the storm-hit area, where buildings were destroyed and cars turned upside down, out of concern that people could be injured while attempting to retrieve possessions.

Mayor Gary Manier said authorities were keeping evacuated residents away out of concern that the remaining structures were dangerously unstable.

Manier estimated that 250 to 500 homes had been destroyed by the tornado, rated as the second-most powerful magnitude of twister, which hit the city east of Peoria.

The storm killed three people in Massac Country, two in Washington County and one in the city of Washington, in Tazewell County, said Patti Thompson of the Illinois Emergency Management Agency.

Illinois State Police spokesman Dustin Pierce said about 120 people were injured in Washington.

Rescue workers in central Michigan found the body of a 59-year-old man entangled in downed power lines on Sunday night.

A 21-year-old man was also killed on Sunday night after a tree fell on his car in the central Michigan town of Leslie.