Four people were injured Monday when a tornado struck their rural Norton County home, state officials said.

The tornado was one of more than a half-dozen reported in northwest Kansas on Monday. There were no serious injuries, said Sharon Watson, a spokeswoman for the Kansas Division of Emergency Management.

At least three homes were damaged or destroyed outside Almena near the Nebraska line, Watson said.

Preliminary reports indicate most of the tornadoes were EF-0 or EF-1 and relatively short-lived, according to the Goodland branch of the National Weather Service. But one tornado, north of Hill City in Graham County, was rated an EF-3, which indicates wind gusts of 136-165 mph.

Tornadoes were also reported in Gove, Sheridan and Phillips counties. Hail as large as softballs was reported in Haskell County, and as large as baseballs in Graham County

No tornadoes were reported in the Wichita area, but powerful straight-line winds are blamed for damage near Maize and Valley Center. A metal shed was flattened near Hoover and 53rd Street North, and a semi was blown over two miles east of Maize on K-96.

A roof was ripped off a building a mile southeast of Valley Center, and swing set was blown into a bay window of a house in town. Fences were also blown down in Douglass in Butler County as the line of storms moved east.

The strongest winds reported in Sedgwick County were 72 mph at the weather service office in west Wichita, while winds of 76 mph were recorded in Atlanta in Butler County.

The winds downed 14 power poles in the Wichita area, according to Gina Penzig, a Westar spokeswoman. Over the course of the storm, about 7,000 customers lost power. About half of that number regained power by 10 p.m. Monday, and the rest had been restored by about 8:30 a.m. today, Penzig said.

Storm damage surveys were being conducted Tuesday by officials from the Goodland and Wichita branches of the weather service.