BIRMINGHAM, Alabama (Reuters) - A tornado nearly a mile wide ripped through central Mississippi on Saturday, killing 10 people, including three children, and injuring dozens of others, state authorities said.

The tornado struck at least 13 counties, destroying scores of homes and trapping people inside, damaging businesses, blocking highways and knocking out power to thousands, said the Mississippi Emergency Management Agency.

Five people died in Choctaw County, four in Yazoo County and one in Holmes County, said Greg Flynn, spokesman at the agency.

Governor Haley Barbour declared a state of emergency after the first major U.S. tornado of the year.

“It has done huge damage around Yazoo City,” Barbour, who grew up in the city, told CBS television.

“We have fatalities, a number of people that we’re still trying to rescue who are trapped in buildings. But it is a major, significant tornado ... and it did some huge damage and perhaps some fatalities north of here,” Barbour said.

“The Hinds County Sheriff’s Department is sending two dozen deputies and 100 inmates to assist with the response in Yazoo County and clear debris,” the emergency agency said.

The storm system has moved to Tennessee, Alabama and Kentucky, said Greg Carbin, spokesman for the National Oceanic and Atmospheric Administration.