Strong thunderstorms packing possible tornadoes battered parts of the Midwest on Sunday for a second straight day, damaging at least half a dozen buildings and a campground in Iowa and two Oklahoma homes.

Tornadoes were reported in eastern Iowa, western Oklahoma and south-central Kansas, but there were no immediate reports of serious injuries.

In Kansas, a possible tornado touched down in the Lake Afton area southwest of Witchita. Two people were injured when the camper they were in was flipped by the storm, said Sgt. Oscar Thomasson of the Sedgwick County Sheriff's Department.

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A possible tornado swept through the northeast part of Linn County, Iowa, destroying campers at a campground near Central City and causing "significant" damage to about a half-dozen homes and buildings in its path, said Mike Goldberg, the county's emergency coordinator.

No injuries had been reported about three hours after the storm, and Goldberg said "it's looking favorable" that there wouldn't be any. Teams were still checking homes one by one in the areas hardest hit, including at the campground, he said.

Strong to severe thunderstorms moved across the southern two-thirds of the state throughout the afternoon, with some areas seeing nickel- to quarter-sized hail.

Power outages were reported Sunday in eastern Iowa and western Oklahoma, while utility crews in southern Michigan worked to restore power to thousands of homes and businesses blacked out by thunderstorms that raked the region a day earlier with wind up to 70 mph.

A mobile home and a frame home were damaged Sunday by a possible twister in Ellis County, Okla., said state Department of Emergency Management spokeswoman Michelann Ooten.

Numerous roads and bridges were closed because of heavy rainfall that accompanied the storms on back-to-back days.