Television footage from locations affected by the tornado showed destroyed houses and debris on the streets -- as well as overturned cars, shredded fences and uprooted trees. According to eyewitnesses, entire settlements were wiped out.

"My town is gone," Mayor Eldridge Walker of Rolling Fork, Sharkey County, told CNN. When he was finally able to leave his house, he found "devastation all around".

Rescue operations ran on Saturday in several counties located about 110 kilometers north of Jackson, the Mississippi capital. The actual extent of the devastation will probably not be known until Sunday.

Woodrow Johnson, a Humphreys County official, told CNN his wife woke him up and they both heard what sounded like a train. Now her house is destroyed.

The US National Weather Service (NWS) issued a tornado and golf ball hail warning for the town of Rolling Fork and surrounding areas around 9 p.m. local time on Friday, urging people to seek shelter. The warning expired in the early hours of Saturday morning, the NWS said. More thunderstorms were expected, but they shouldn't be of comparable magnitude.

Just a few days ago, a tornado near Los Angeles in the US state of California caused considerable destruction. Wednesday's storm ripped off houses and spun cars amid what was an unusually violent storm for the region. In January, a series of tornadoes in the states of Alabama and Georgia killed scores.