By Rich McKay

ATLANTA (Reuters) – Dozens of wildfires burned in the U.S. Southeast on Tuesday, scorching tens of thousands of acres of forest and sending plumes of smoke across hundreds of miles of western North Carolina, northern and central Georgia and parts of eastern Tennessee.

Air quality alerts were issued across swaths of those states, with hazy smoke reaching as far south as Atlanta and north to Knoxville, Tennessee. People in the affected areas were urged to stay indoors or limit outside activity, officials said.

The fires could take weeks to extinguish, and a lack of rain in the forecast has added to concerns, said Wendy Burnett, spokeswoman for the Georgia Forestry Commission.

“The extended drought across the Southeast is the number one culprit,” Burnett said in an interview. “Rain is going to be what it takes to knock this down anytime soon. We’re doing every rain dance we know.”

North Carolina has been the hardest hit with more than 36,800 acres in western parts of the state burning in 15 major fires that are in various stages of being controlled, according to the governor’s office.

North Carolina Governor Pat McCrory has ordered a state of emergency in 25 counties. The fires closed parts of the Appalachian Trail, along with parks, roads and stretches of highways, and forced the evacuation of about 1,000 residents, the governor’s office said in a statement.

In Georgia, more than 28,000 acres are burning, according to Burnett, forcing the evacuation of about 60 homes. The largest fire is on the Rough Ridge in the Chattahoochee-Oconee National Forest, she said, with about 19,500 acres burning.

That blaze was caused by a lightning strike, said U.S. Forest Service spokeswoman Michelle Burnett, while several others on federal land remain under investigation.

In Tennessee, nearly 16,000 acres have burned in 67 active fires, according to the state Department of Agriculture’s Division of Forestry.

Arson is suspected in at least one major fire in Tennessee, according to local news accounts. Others were caused by camp fires, farm equipment and a tossed cigarette, officials and state websites said.

“It’s been so dry, that one spark is all it takes to burn a forest,” said the Georgia Forestry Commission’s Burnett.

(Editing by Colleen Jenkins and Alan Crosby)