UPDATE: Fire still burning in Twelve Mile Swamp; drivers urged to be careful

Update:

Authorities are still monitoring a fire near U.S. 1 and International Golf Parkway in the Twelve Mile Swamp Conservation Area, according to the Florida Highway Patrol. 

Drivers should use caution in the area because of smoke and fog, which could have an impact on visibility. Drivers should reduce their speed and use low beam headlights at night. 

Previous version:

The cause of a 15-acre fire in the woods off U.S 1 and International Golf Parkway is under investigation by the Florida Forest Service.

"It was in the wooded area in the Twelve Mile Swamp Conservation Area, so no structures were involved," said Greg Dunn, senior forester.

The fire, which was contained, was reported to the forest service at about 1:30 p.m., Dunn said.

The fire was first believed to be a prescribed burn, said Sgt. Dylan Bryan of the Florida Highway Patrol.