06:51 (GMT+4) The storms, raging in the southeast of the United States at the weekend, killed at least 18 people, injured many, inflicted heavy damage on homes and cut power, Sputnik reported.
According to USA Today newspaper, 14 people were killed in Georgia and four in Mississippi.
The search and rescue operations are reportedly underway in Georgia.
22:03 (GMT+4) Severe weather has killed 11 people and injured 23 in the US state of Georgia, emergency officials said, BBC reported.
Tornado warnings were issued for parts of the state overnight on Saturday.
Four people were killed by tornadoes in Mississippi earlier in the day.
The Georgia Emergency Management Agency said victims were in the southern Cook, Brooks and Berrien counties.
Seven of those killed were at a mobile home park in Cook County apparently struck by a tornado overnight.
Cook County coroner Tim Purvis said numerous mobile homes had been "levelled" before dawn on Sunday in the park near the city of Adel. He said emergency teams were still searching for survivors.
Mr Purvis estimated that the park has about 40 mobile homes in total, and roughly half were destroyed.
In Brooks County, coroner Michael Miller said two people died when an apparent tornado tossed a mobile home around 100 yards into the middle of Highway 122.
Swathes of the south-eastern United States have been hit by storms over the weekend.
In southern Mississippi, four people died in the path of a tornado with winds above 218 km/h (136 mph).
The National Weather Service in Atlanta/Peachtree City said a "significant tornado outbreak" was expected on Sunday around the Florida-Georgia border, with storms expected from noon onwards.
In a tweet, it said rainfall had been significant in the past 24 hours, with the city of Charlotte getting 13.6cm (5.3 inches).
A severe thunderstorm warning is in effect for northwest Florida.
The Georgia Emergency Management Agency issued advice on the best and worst places to shelter from a tornado late on Saturday, advising locals in the path of a tornado to cover themselves with blankets or a mattress for protection.
It said the safest place to be is "a basement or interior room, stairwell, or hallway on a low floor".
Windows, doors, and outside walls are to be avoided.
It also warned against underestimating flash floods, saying just six inches of fast-moving water can knock a person off his or her feet, and two feet can sweep away a full-sized car.