(CNN) -- Two major wildfires have burned more than 18,000 acres along Florida's eastern coast, state officials said Tuesday.
"At this time, we have been fortunate that the fires have not resulted in any human loss," said Department of Agriculture and Consumer Services Commissioner Adam Putnam. "All Floridians should use caution in and around these areas to safeguard themselves from smoke, ash and the flames themselves."
One fire, which began Monday in northern Brevard and southern Volusia counties, has destroyed a mobile home, several outbuildings and several camp structures, the Agriculture Department said in a news release. It had scorched more than 16,000 acres and was being driven by high winds.
The Florida Division of Forestry deployed 22 tractor plow units, two helicopters and two air tankers to help fight the fire, which was about 25% contained, the department said. More than 150 personnel are engaged in the effort to contain the fire, it said.
Cliff Frazier, a wildfire mitigation specialist with the Florida Division of Forestry, said crews will work throught the night and traffic on some roads may be affected.
Meanwhile, a second wildfire had burned close to 2,000 acres in St. Johns County, south of State Road 206 on Interstate 95, below St. Augustine, the department said. It also was about 20% contained.
That blaze crossed I-95 and U.S. 1, causing both roads to be closed at times because of smoke and poor visibility, the department said.
The Florida Division of Forestry has 15 tractor plows and three brush trucks with 20 county fire department engines, six county water tenders and three bulldozers assisting with the fire, the Agriculture Department said. More than 137 people are working on snuffing that fire. Its cause was unknown Tuesday afternoon.
As winds shift, the first fire could be blown to the south and into more heavily populated areas of Brevard County, said Fred Jodts, division chief for Brevard County Fire Rescue.
Light rain fell Tuesday morning, helping to slow the fire and provide firefighters more time to organize their response, but it didn't eliminate the danger, Jodts said.
"It gives us a break. It's not going to put the fire out," he said.
A voluntary evacuation in the city of Mims was lifted Tuesday evening and shelters were closed, according to the Brevard County Office of Emergency Management. The agency reported a Brevard firefighter suffered second-degree burns to the face.
The cause of the fire is unknown, Frazier said, but he added that the combination of severe freezes this winter that killed surface vegetation and low rain totals made conditions ripe for a fire.
Lee Francis got an upfront look at the fire when it came within a half-mile of the farm where she lives with her husband. They had gone to a police line to check on the situation when the fire jumped U.S. 1 and headed for their home, she said. They returned home to hose down the house, yard and vehicles amid the fire's orange glow.
"We could see flames and the smoke was very thick," she said. "We could see when the firefighters would get it beat back, the glow would subside, then it would flare up again."
CNN's Shawn Nottingham and John Couwels contributed to this report