A dangerous weekend weather system has killed at least 15 people in the South, with Georgia officials on Sunday reporting that 11 had died in severe weather still threatening the region.

Georgia Gov. Nathan Deal declared an emergency for seven counties in the south-central part of the state, warning that dangerous conditions persisted and could reach north to the Atlanta area.

“I urge all Georgians to exercise caution and vigilance in order to remain safe and prevent further loss of life or injuries,” Deal said in a news release.

The system also had injured 23 people in southern Georgia, the Georgia Emergency Management Agency said. Photos from the affected areas showed collapsed buildings, homes with their roofs torn off, toppled trees and fields littered with debris.

Seven of the fatalities occurred at a mobile home park outside Adel, Georgia, near the Florida state line, local media reported. The Cook County Coroner’s Office told Reuters that search and rescue efforts were ongoing.

First Baptist Church Adel was sheltering more than 50 people, said Pastor Bill Marlette, who had just informed a family that two of their relatives were among the dead.

“There’s a lot of hurting people right now,” he said, adding that many in the hard-hit mobile home park escaped with only the clothing on their backs.

“There’s just a sense of shock. You always think it happens somewhere else, but when it happens to you, it catches you off guard,” he told Reuters in a telephone interview.

The deadly storms in Georgia, which also reportedly killed four people in Brooks and Berrien counties, followed a predawn tornado in Mississippi on Saturday that killed four people and caused widespread property damage.

The system prompted weather forecasters to issue a rare, “high risk” warning of severe storms threatening parts of southern Georgia, north Florida and Alabama on Sunday, the first such warning since 2014.

“These could be the kind of tornados you don’t want to mess with,” said Rich Thompson, lead forecaster at the National Weather Service Storm Prediction Center in Norman, Oklahoma.

Severe winds toppled trees and downed power lines in Georgia and northern Florida on Sunday, the agency’s website reported, and hail was sighted in northern Florida.

The severe weather could extend to central Florida and South Carolina into Sunday evening, menacing population centers in Jacksonville, Gainesville and Tallahassee in Florida; and Savannah and Albany in Georgia, the weather service said.