UPDATE: More than 70 fires - including 25 reported on Thanksgiving - are burning in Tennessee, state officials reported Thursday.

Major blazes include a Walland fire in Blount County that's been burning for a week.

The fires continue to have an effect on our air here in East Tennessee. A Code Orange alert was issued for Thanksgiving and it remains in effect for Friday.

The alert is in place for the Knoxville area as well as the Great Smoky Mountains.

Under a Code Orange alert, the air is considered unhealthy for sensitive groups. People with heart and lung disease, older adults and children are at a greater risk while it's in effect.

Recent fires in Tennessee have consumed more than 26,000 acres so far. For the year, more than 40,000 acres have burned.

Fire officials say about half the fires burning now are suspected arson.

PREVIOUS REPORT: Wildfires continue to burn across the state, burning more than 42,000 acres so far this year, as firefighters from across the country help on the front fire lines.

Fueled by the extreme drought, firefighters are currently battling 72 fires burning on more than 26,000 acres in Tennessee, as of Nov. 24, according to the Division of Forestry. Twenty-five new fires were reported in the last 24 hours, covering 478 acres.

RELATED: Hundreds of firefighters cycling through Knoxville Mobilization Center to fight wildfires

Major fires are still burning in several East Tennessee counties:

o Little Brushy (Morgan) 100 acres, 10% contained
o Stoney Fork (Campbell) 750 acres, 50% contained
o Beech Grove Rd (Anderson) 400 acres, 75% contained
o East Miller Cove (Blount) 1,459 acres, 80% contained
o Bald Knob Rd. (Morgan) 790 acres, 100% contained
o Lee Valley ("Boy Scout Camp") (Hamblen) 311 acres, 100% contained
o Mill Creek (Morgan) 100 acres, 100% contained
o Cool Branch Cove (Hancock) 350 acres, 100% contained
o Old Mountain Rd (Grainger) 230 acres, 100% contained
o HWY 165 (Monroe) 690 acres, 100% contained
o Neddy Mt (Cocke) 1,076 acres, 100% contained
o Mile Marker 156 (Campbell) 1,010 acres, 100% contained
o Flippers Bend (Hamilton) 981 acres, 100% contained
o Poe Rd. (Hamilton) 712 acres, 100% contained
o Mowbray (Hamilton) 899 acres, 98% contained

There's a small chance of rain on Wednesday, with a greater chance next week, which may give firefighters some relief.

Gov. Bill Haslam visited fire crews in both Hamilton and Blount counties on Wednesday.

He said statewide, the cost of fighting these fires will cost more than $5 million dollars. He says putting them out is a top priority.

"These folks are working on the side of mountains and they are working long hours and it's not like they can say oh we are getting tomorrow off because it's Thanksgiving. They are committed to getting these fires out," Haslam said Wednesday.

RELATED: Aerial view of wildfires in East Tennessee

RELATED: FEMA authorizes federal reimbursements for Tennessee and Kentucky to battle wildfires

Haslam said with so many fires started by humans and started negligently, there is a fight to prosecute those people as firefighters continue to protect homes and people

"It’s incredibly frustrating, by our count over 50 probably, we think about 57 percent of these fires we have across the state were set intentionally by arsonists and as I said there is no excuse for that. We have men and women putting their lives at risk. We have people whose homes are being threatened by it and there’s just no excuse for that and we are going to do everything we can to pursue those folks,” he said.

Beginning 6 a.m. Thursday, part of Old Walland Highway will be closed -- from Coulters Bridge at Tuckaleechee Pike to Chilhowee Inn at Old Walland Highway and Dalton Lane. The closure affects vehicles and bicycles.

The closure is to help firefighters at the Walland fire in Blount County.

The state's arson reward fund is now at $2,500 for a tip that leads to an arson arrest and conviction. The arson hotline is 1-800-762-3017 and is answered 24 hours a day.

A burn ban remains in place across the state. Here's what is and is not allowed during the burn ban.