The Salvation Army has dispatched emergency disaster personnel to southeastern USA where tornadoes have left at least 350 people dead.

More than 200 tornadoes were reported across six southern states on Tuesday and Wednesday, making it one of the worst ever tornado outbreaks in US history.

The worst hit state was Alabama, where more than 250 people were killed. The town of Tuscaloosa suffered extensive damage when it was struck by a mile-wide tornado on Wednesday.

Other states to be hit were Tennessee, Mississippi, Kentucky, Louisiana, Georgia and Virginia.

Speaking to reporters on Friday, the mayor of Birmingham, Alabama, said it seemed like “a bomb has been dropped”.

"Whole neighbourhoods of housing, just completely gone. Churches, gone. Businesses, gone,” he said.

The Alabama-Louisiana-Mississippi Division of The Salvation Army has mobilised 10 feeding units to affected areas.

They are providing food, drinks and spiritual support to storm victims in Tuscaloosa, Guntersville and Lauderdale County in Alabama, and Montpelier and Oxford in Mississippi.

Mobile feeding units from the Kentucky-Tennessee Division are serving victims in Chattanooga and Cleveland in Tennessee.