Aug. 8 (UPI) -- Firefighters set controlled fires Saturday to clear vegetation around the Apple Fire, which has spread to more than 32,400 acres in Southern California.
The wildfire along San Bernardino Mountains near Riverside has burned through 32,412 acres with 35% containment, according to a U.S. Forest Service update.
Firefighters planned Saturday to fly firefighters to a remote area of San Gorgonio, located in the eastern San Bernardino Mountains, to clear vegetation. They have already set controlled fires to clear vegetation around the blaze.
The San Gorgonio wilderness area is closed to all use, the San Bernardino National Forest tweeted.
The California Department of Forestry and Fire Protection called the controlled fires a "firing operation" along the eastern edge of the fire to decrease fuels in order to stop the fire from spreading to the east.
"Due to the hard work of the firefighters on this firing operation, smoke impacts to the communities east of the fire should be diminished," the Cal Fire statement said.
An estimated 2,845 firefighters, 18 water-dropping helicopters and two air tankers have been fighting the fire located near Banning Canyon, Cal Fire said.
The malfunctioning exhaust system of a diesel vehicle sparked the fire on July 31, which has burned through parts of Oak Glen and chaparral and brush in Banning Canyon in southwest San Bernadino County, just outside Riverside.
It has destroyed four homes, eight other structures and a firefighter sustained a head injury when a falling tree branch struck him on Thursday. His identity and condition have not been released.
An estimated 7,800 people were evacuated from 2,600 residences during the fire's peak.
Non-mandatory evacuation warnings remain in effect for Forest Falls, Morongo Valley, Rimrock and Pioneertown, according the U.S. Forest Service, which estimates the fire will be contained by Aug. 17.