Aircraft firefighting efforts were delayed recently in the Cajon Pass area because as many as five drones flew around the blaze, an official told a California legislative hearing this week.
Ken Pimlott, Cal Fire chief, said the fire burned 4,250 acres while destroying seven homes and multiple properties, the Los Angeles Times reported.
The actions of these hobbyists prompted officials to share their concerns with lawmakers in Sacramento on Tuesday.
"The most immediate and critical issue we face is the serious threat that these drones pose with the irresponsible use of them," said Pimlott, according to the newspaper. "It is placing our air crews, our pilots, in immediate danger."
Pimlott told the Californian news station KCRA-TV that one of Cal Fire's aircraft was "50 feet away from a midair collision" with a drone when authorities were returning from the fire, "potentially killing the pilot and the air crew and placing people on the ground at grave risk."
More than a dozen instances of drones interfering with wildfire battles have been reported this summer, he told the station.
Authorities have not identified who is flying the drones, and no one has brought down any of these aircraft either. But the hearing of the Joint Legislative Committee on Emergency Management is exploring ways to confront drone use near fires.
"It is against the law currently to interfere with police, with the duties of firefighters, the duties of EMT or ambulance personnel," Philip Horner, consultant to the legislative committee, said to The Sacramento Bee on Monday. "Yet now we have these drones doing that and they're unregulated."
Lt. Barbara Ferguson of the San Bernardino County sheriff's office told the hearing that, when firefighters issued a warning by turning on helicopter sirens, three unauthorized drone operators left the scene but two remained, The Press-Enterprise reported.
She said a drone even trailed a spotter plane into the fire zone area.
"Unless we have witnesses on the ground that actually see them operating those ... it is very difficult to investigate who those operators are," Ferguson said during the Sacramento hearing, the paper reported.
One Senate bill will make drone use over wildfires a state crime worth up to six months in jail with a fine as high as $5,000.
The federal government also has taken notice of the use of drones around wildfires. The Federal Aviation Administration has been enforcing a temporary ban on the use of drones in areas with wildfires, such as Washington, California, Idaho, Oregon, Montana and Nevada, since Saturday "to provide a safe environment for fire fighting aircraft operations."
Meanwhile, three firefighters were killed and three to four others were injured, at least one critically, on Wednesday as raging wildfires advanced on towns in north-central Washington, authorities said.
Okanogan County Sheriff Frank Rogers said the deaths, in a wildfire near Twisp, had been confirmed, but he said he was not immediately releasing further details about the circumstances. One firefighter had been taken to Harborview Medical Center in Seattle in critical condition, a nursing supervisor there said.
The news came after officials urged people in the popular outdoor-recreation centers of Twisp and Wintrop, about 115 miles northeast of Seattle, to evacuate as fires in the area covered about 50 square miles. The Okanogan County Emergency Management department issued the order for the towns, which combined have a population of about 1,300.
Information for this article was contributed by staff members of The Associated Press.
A Section on 08/20/2015