If you need another reason (besides common sense) not to fly your drone over a dangerous situation, such as wildfire, here’s a good one: you could be charged with murder.

Authorities in in San Bernardino County, California issued a stern warning Wednesday by saying “if an intentional act of a drone was to cause one of these wonderful men and women fighting fires to go down and be injured or worse scenario killed or another civilian on the ground, we will – we will prosecute you for murder.”

The warning comes after an increasing amount of drones being spotted flying over wildfires in California, forcing firefighters to ground aircraft and causing some of the fires to spread faster and further.

Ars Technica rounds up the recent incidents:

The first incident occurred in late June, when interference from a hobbyist drone flying over the Lake Fire in San Bernardino County forced the US Forest Service (USFS) to divert three planes carrying flame retardant, costing USFS $10,000. The drone was reportedly flying higher than the legally allowed 400 feet above the ground, and USFS had issued a temporary flight restriction over the wildfire, as it does commonly during wildfires. The drone operator was not found. Two weeks later, during the Mill 2 fire (which was also in San Bernardino County), the Los Angeles Times reports that “officials had to briefly suspend a tanker after a drone was spotted flying over Mill Creek Canyon near California 38.” Just a few days later, firefighting helicopters were grounded due to the proximity of as many as five amateur drones during the North Fire. The fire engulfed brush near I-15 north of Los Angeles and quickly jumped onto the highway, sending drivers fleeing from their cars, 20 of which were destroyed.

Officials also announced a total of $75,000 in rewards (PDF) for information leading to the capture and conviction of anyone who flew drones above these recent fires.

“We don’t want to put our firefighters in harm’s way,” San Bernardino County Sheriff John McMahon says. “A collision between a drone and a firefighting aircraft could be devastating.”

Flying drones recklessly is a growing concern among regulators and legislators. Senator Dianne Feinstein (D-Calif.) recently introduced the Consumer Drone Safety Act that looks to shore up safety features on consumer drones and the federal laws that govern their operation.

And California State legislators Mike Gatto (D-Glendale) and Ted Gaines (R-El Dorado) introduced a bill to permit a $5,000 fine and up to six months in jail for “intentional and reckless” drone operation during a fire.