CHICAGO - Crews in central Oklahoma on Monday (Feb 27) were assessing the damage and clearing debris left behind by a string of rare February tornadoes that roared through the area overnight, knocking out power to thousands of customers and injuring a dozen people.

In Norman, 12 people were taken to the hospital after suffering minor injuries in the storms that rolled through and near the city at around 11pm local time on Sunday.

None of the injuries were life-threatening, Norman chief of police Kevin Foster said during a news conference on Monday.

Several homes, businesses and schools in Norman, which has about 128,000 residents, were damaged in the storms, he said.

The twister was one of seven that touched down in Oklahoma and two more were reported in Kansas overnight, the National Weather Service said.

Some 13,000 homes and businesses were without power across Oklahoma, Poweroutage.us reported.

Video footage and photographs of the destruction on local news and social media showed power lines lying in the middle of roadways, debris strewn across neighbourhoods and roofs ripped off buildings.

One photo showed a red sedan flipped over and resting on top of another vehicle.

"A lot of real strong wind," George Reich, a homeowner in Shawnee, a town east of Oklahoma City, told an ABC affiliate. "Wood and debris started flying. I jumped in the backseat of a car in the garage real quick."

Experts say the growing frequency and intensity of such storms, interspersed with extreme heat and dry spells, are symptoms of climate change.

"It was pretty rare, historic in the amount" of wind shear, said Bruce Thoren, a National Weather Service meteorologist in Norman, regarding the Oklahoma twisters, noting that the state has seen only 51 tornadoes in February since 1950.

Four additional twisters were reported in Illinois on Monday morning but none caused significant damage, according to online reports by the National Weather Service.

By Monday afternoon, the service had issued several additional tornado advisories for parts of Indiana, where they warned of strong storms and damaging winds throughout the day.

"Take cover now! Move to a basement or an interior room on the lowest floor of a sturdy building," the weather service said in one tornado warning for the Indianapolis area on Monday afternoon.

The rough weather comes after days of a winter storm clobbered the US Plains, Midwest and Great Lakes regions.

More than 155,000 homes and businesses in Michigan remained without power on Monday, Poweroutage.us reported.

Parts of California spent the weekend dealing with heavy snows in higher elevations, rain and hail in the flatlands and frigid temperatures in parts of the state that are known for its mild weather.

Source: Reuters