According to officials at the Tennessee Emergency Management Agency, the 10 deaths were in communities near Nashville, including seven fatalities northeast of the city in the outskirts of Gallatin in Sumner County.

Randy Harris, of the Tennessee emergency management agency, said the toll dropped from 11 to 10 because a missing person in Sumner County was found to be alive.

What had been stately brick homes near Gallatin were damaged, and rubble was strewn across upmarket neighbourhoods. Several people were rescued after being trapped in their cars by debris.

In Warren County, where the other three deaths occurred, authorities said some mobile homes were destroyed and a truck overturned.

The winds knocked over walls at Volunteer State Community College in Gallatin where 200 students huddled inside a building as the storm approached.

Heavy damage

Despite the heavy damage to the campus, the injuries were mostly minor cuts and bruises.

The National Weather Service's storm prediction centre reported 42 tornadoes on Friday in Tennessee, Mississippi, Alabama, Indiana and Kentucky. The violent weather grew out of a powerful storm system working its way across the nation.

Warning sirens sounded across central Tennessee on Friday as dark funnel clouds sent tornadoes spinning to the ground, accompanied by heavy rain and hail, some as big as baseballs, witnesses said.

Bill Purcell, the mayor of Nashville said: "Cars were tossed around."

A tornado damaged a hospital in Ashland City, though no one was hurt. Patients had to be transferred to another facility.

A pylon carrying power lines collapsed on a home in Ashland City. The storm up-rooted trees and downed power lines, knocking out power to thousands, authorities said.

Ironically, authorities were holding emergency response drills in Nashville to prepare in the event several disasters struck simultaneously. Earlier on Friday, volunteers simulated a plague outbreak, a skyscraper collapse and a bomb blast at a popular venue.

Purcell said: "We were all highly mobilised because of this exercise."