Firefighters have announced progress on containing two of the largest wildfires burning in the North Carolina mountains, but they have warned that fire danger remains from dry and windy conditions.

The news was worse in South Carolina, where two fires nearly doubled in size on Wednesday, but crews kept the blazes away from homes and other structures.

Hundreds of people have been asked to leave their homes in North Carolina and South Carolina as a half-dozen large fires are burning in the Blue Ridge Mountains, spreading smoke into places like Greenville.

Millions of fallen trees from September's Hurricane Helene are both providing fuel for the wildfires and hindering firefighters' use of logging roads and paths.

The North Carolina Forest Service said that the Black Cove Fire and Deep Woods Fire were each more than 10 percent contained on Wednesday night, after days of reporting zero containment for the two blazes.

The fires have scorched nearly 10 square miles (26 square kilometres) combined, but the size of the area burned has largely remained the same since the previous day.

About 250 homes have been evacuated in Polk County, where the fires are centered. About two dozen homes and outbuildings have been destroyed in Polk County, spokesperson Kellie Cannon said.

Firefighters have managed to save most of the structures near the fires. Only one injury has been reported — a firefighter in North Carolina got his leg caught under a tree, officials said.

South Carolina fire update

South Carolina fire officials called for their first round of evacuations on Tuesday night and more throughout the day on Wednesday.

Two fires are burning — a larger one inside Table Rock State Park in Pickens County that has consumed 7.1 square miles (18.4 square kilometres) and another one on Persimmon Ridge in Greenvill e County that has burned 2.4 square miles (6.2 square kilometres), according to measurements from the air on Wednesday afternoon, Officials said the fires have likely grown since then.

About 250 homes are in the Pickens County evacuation zone with more in neighbouring Greenville County, authorities said.

The fires are about 8 miles (12.5 kilometres) apart, and winds are strong enough that authorities decided to evacuate the area between the two fires.

North Carolina fire update

Wednesday's dry weather led to several new fires in western North Carolina and prompted Gov. Josh Stein to declare a state of emergency in 34 western counties. At least nine fires were active in that part of the state, officials said.

“Our State Emergency Response Team is responding with every tool at its disposal. Please stay safe and stay alert for any evacuation orders if the fires spread to an area near you,” Stein said in a statement.

Late on Tuesday, a wildfire started in far western North Carolina not far from Bryson City. Police were evacuating dozens of people as the fire spread to nearly 1 square mile (1.6 square kilometres).

The fires in South Carolina have been caused by humans.

Authorities from local fire chiefs all the way to South Carolina's governor are urging people to heed burn bans in both states and stop setting fires at campsites or burning garbage.

“We have people going out in the woods and in their backyards and starting fires when the wind is blowing and everything is dry,” South Carolina Gov. Henry McMaster said. “We just have to use common sense. People get out in nature and they forget how dangerous it can be."