PALM CITY — A brush fire that has been burning for several days in a wooded area west of Palm City near Interstate 95 has spread over 300 acres, but it is now mostly underground and contained, Florida Forest Service and Martin County Fire Rescue officials said Saturday.

“Underground fire doesn’t have exposed flames on top, but it’s like a bed of charcoal underneath the ground,” said David Grubich, a spokesman for the Florida Forest Service. Organic material in the soil fuels underground fires, he said.

The brush fire started Thursday in the wooded area off I-95 and around state Route 714 and Southwest Martin Highway. It initially spread over 30 to 40 acres, as embers got across the control lines and expanded the fire, Grubich said.

Palm City brush fire: Wildfire no longer threat to homes and no damage reported

Fire crew personnel are at the scene suppressing the embers by extinguishing or removing burning material near control lines, felling damaged trees, and cooling ash pits, Grubich added.

Martin County Fire Rescue has stationed two engines, two brush trucks, and one tanker on the scene to work on hotspots, overhaul the area, and watch for spot fires, said Martin County Fire Rescue spokesman Cory Pippin. The fire is estimated to be 90% contained, he said.

There were no reports of injuries or damages to residences or structures. Some homes near the fire were evacuated on Friday evening, but residents have since been allowed to return, Grubich said.

Smoke from the fire was visible Saturday afternoon near Stuart West Cobblestone, a residential community on Southwest Martin Highway off I-95. There are no road closures along the I-95 and Southwest Martin Highway, and traffic is flowing normally.

Underground fire can smolder for weeks, even without visible flames on the surface, Grubich said. They can also reignite, even if it appears to be extinguished on the surface. “This was actually a fire that we had suppressed at 58 acres. And then that fire ember got out from that, got across the line, and as a result, we got 300 acres now,” Grubich said.

Residents are urged to report any signs of fire immediately by calling 911. Homeowners should protect their properties from flying embers that can travel up to a mile from the fire by cleaning gutters and eaves to remove pine needles, leaves and other debris, Grubich said.

People living near the wildfire should check the air quality to stay informed, seek cleaner air indoors, use air conditioning without bringing in outside air, limit outdoor activities, wear an N95 respirator, consult health care providers for advice, and stock up on essentials to minimize outdoor trips, according to U.S. Fire Administration guidelines.

Wildfires are more likely in drought conditions such as Florida is experiencing right now, said Grubich. Lightning strikes can ignite them in this weather. The cause of the fire remains under investigation.

This article originally appeared on Treasure Coast Newspapers: 300-acre underground brush fire continues to burn, largely contained