At least seven people have died in storms in the southern US

At least seven people have died after tornadoes and violent winds ripped through the US South, as a series of storms expected to continue for days takes hold.

Deaths were recorded in western Tennessee, Missouri and Indiana on Wednesday and Thursday, in areas where homes were flattened and debris flew miles-high.

The toll could rise in what the National Weather Service described as "once-in-a-generation" storms in flood warnings issued on Thursday.

Dozens of severe weather alerts, including tornado watches and flash flood warnings, have been issued from Texas to Pennsylvania.

The storm system will threaten "significant, life-threatening flash flooding" until Saturday, the NWS said.