The National Weather Service (NWS) said a tornado struck Mobile, Alabama, home to about 200,000 people, at about 5 p.m. local time (2300 GMT). There were reports of damage to trees and widespread power outages, along with some structural damage, but no injuries or fatalities.

Tornadoes also touched down in Mississippi, Texas and Louisiana, flattening houses and causing some injuries, according to the NWS.

The wild Christmas weather was expected to continue into early Wednesday - the NWS' Storm Prediction Center forecasted the development of "a few strong tornadoes and thunderstorm wind damage over parts of the southeast" this evening and overnight.

It warned that tornadoes at night at this time of year can be particularly dangerous because they are usually fast-moving and obscured by rain and darkness. Areas mostly likely to be hit by strong storms include southern and eastern Alabama, the Florida Panhandle and southwest Georgia, the NWS warned.