At least four people have died as an outbreak tornadoes has swept across the US southern state of Mississippi.

Two of the deaths happened in Jones County with the remaining fatalities and 20 injuries occurring in Marion County, concentrated near the town of Columbia, about 50km west of Hattiesburg.

The state governor, Phil Bryant, issued a state of emergency for both counties, speeding up the availability of state resources for disaster relief.

"Our thoughts and prayers are with the families and friends of the four individuals who lost their lives today during the severe weather that pushed through the state," said Governor Bryant in a statement.

It is reported that almost 7,000 homes were without electricity as power lines were brought down.

The tornadoes were spawned by a cluster of thunderstorms which originated over southern-central Louisiana before tracking northeastwards. Although less frequent than during the early summer, tornadoes can occur at any time of the year.

The National Weather Service has issued warnings for flash flooding across parts of the Florida Panhandle and southwestern Georgia. Much of the region is subject to tornado watches.

A much wider area has been hit by torrential rain. The town of Tallahassee in northeastern Florida recorded 188mm in less than 24 hours. Louisiana, Georgia and the Carolinas are all experiencing flooding rain.

The bad weather coincides with a busy period on the roads ahead of Christmas.

Source: Al Jazeera