NAPA, Calif. - Cal Fire is investigating whether private citizens are setting backfires near the Glass Fire.
A spokesperson for the agency wouldn't say whether the reports came from Napa or Sonoma County, the Santa Rosa Press Democrat report.
Firefighters said backfires are an effective, but highly risky technique, and should only be conducted by trained firefighters.
They added that it can pull resources away if flames get out of control.
On Tuesday evening, Cal Fire reported that the Glass Fire had scorched 67,050 acres of earth and was 54% contained.