Brandon, Miss. ? Lines of violent thunderstorms rolled through the South on Wednesday, blowing apart mobile homes, snapping dozens of trees and power lines, and ripping the roof off a school while classes were in session.

A tornado touched down in Mississippi during a storm siege. There were no immediate reports of deaths, but officials said at least eight people were injured, including one in critical condition. Gov. Haley Barbour declared a state of emergency in storm-damaged areas.

The hardest-hit section of Mississippi was rural Rankin County, southeast of Jackson. At least 17 homes were destroyed in the county, and 15 others had major damage, said Amy Carruth, a Mississippi Emergency Management Agency spokeswoman in Brandon.

National Weather Service officials said the tornado was rated an F3 on the Fujita scale, with winds ranging from 158 mph to 206 mph.

Violent storms continued during the midafternoon hours on Wednesday, triggering numerous new reports of possible tornadoes aloft and flash flooding. Tornado threats returned to many of the counties pounded during the morning hours.

Another tornado destroyed about eight homes and damaged about a dozen other houses, barns and workshops near Heflin in northwest Louisiana. One mobile home was torn down around a woman and her two sons.

“I just hit the floor with my two little boys and covered their heads as best I could,” Jennifer Gray said. “And the next thing I know it feels like we’re outside. There were no walls, no roof. It was still storming on top of us.”

Dark clouds roll over Cecil B. Pos Long Field in Paris, Texas, where a high school baseball game was canceled ahead of strong thunderstorms in the state's northeast region. Storms throughout the South on Wednesday injured at least eight people and damaged property.

Storm watches and warnings also were posted for sections of Alabama and the Florida Panhandle, the weather service said.

East of Rankin County, high wind blew the roof off Mize High School while classes were in session, school district officials said.

School officials moved the 650 students onto the first floor of the two-story school before the tornado hit and no one was injured, said Supt. Warren Woodrow. “The teachers did a good job of holding it together,” he said.