A tornado has torn through the southern US city of Tupelo, blowing the roofs off homes and tearing down trees and power lines, but there have been no immediate reports of injuries.
"Emergency crews are currently assessing the degree of damage," the mayor's office said in a statement on Facebook, urging people to stay in their homes.
Social media images and videos showed the roofs of many homes and buildings blown away, electricity lines down and streets in the Mississippi city swamped with debris following Sunday's twister.
The tornado also wreaked damage in southeast Pontotoc County and Calhoun City, television station WTVA said.
"Calhoun City was hit hard tonight," the county sheriff, Greg Pollan, said on Facebook. "Light poles have been snapped off. Trees in a few homes. Trees on vehicles. Damage to several businesses."
Strong storms are expected to continue moving east across north Mississippi and southwest Tennessee early on Monday, weather authorities said.