No injuries were reported in a Sunday afternoon brush fire that covered nearly 5 acres off Ga. 400.

Forsyth County Fire Capt. Jason Shivers said the blaze started about 2:53 p.m. near what is known as "the lake bridge" in northern Forsyth.

The bridge spans Sawnee Creek, which was once considered part of Lake Lanier when water levels were higher. The area has since withered under the ongoing drought.

Shivers said firefighters worked from two different locations, Ga. 400 and Pilgrim Mill Circle, to put the flames out and had the site cleared by about 6:30 p.m.

There were several minor wrecks as traffic slowed on both sides of Ga. 400 as a result of the blaze, Shivers said.

The northbound lanes were more affected, he said, because of fire equipment on the road. The backup in the southbound lanes was contributed to onlookers.

Shivers said it is not clear what started the blaze.

"With there not being any structural damage and no witnesses, there's just not any way to come any closer to a determination," he said.

The fire department's wildland team set backfires that extended from beneath the bridge to prevent future blazes, Shivers said. A backfire is a controlled burn used to eliminate fuel, such as dry debris.

"It's never performed without adequate manpower to watch the fire line and make it eat the fuel in the manner that you want it to," he said. "It's always done in a controlled manner."

Shivers said a powerful windstorm in July 2007 scattered large amounts of debris, including pine trees and dead brush, in the area.

"All of that brush is what laid in the path of this fire and now it's had almost two years of being dead and dying and drying on the ground to really make it available fuel," he said. "A big concern was keeping the fire away from the fuel stores that were on the ground."

He said three fire department engines, two brush trucks, one tanker and 17 personnel responded to the fire as well as the Georgia Forestry Commission.