An employee of California's state fire protection agency has been arrested on suspicion of starting five forest fires in recent weeks, local officials have said.

Robert Hernandez, a 38-year-old apparatus engineer at Cal Fire, was charged with five counts of arson, and is due to appear in court on Tuesday.

He is suspected of igniting the blazes while off duty in three areas of northern California between 15 August and 14 September.

Thanks to the quick response by firefighters and local residents less than an acre (0.4 ha) of wildland was burned, the officials said.

“I am appalled to learn one of our employees would violate the public’s trust and attempt to tarnish the tireless work of the 12,000 women and men of Cal Fire,” agency chief Joe Tyler said.

Hernandez was arrested on Friday, and booked into Sonoma County Jail on Friday.

He is suspected of starting the five fires near the towns of Geyserville, Healdsburg and Windsor, some 56-62 miles (90-100km) north of San Francisco.

Apparatus engineers at Cal Fire are responsible for operating and maintaining fire engines and water tanks during emergency responses.

California has seen a number of severe wildfires during the summer, with nearly three times as much acreage burn as during all of 2023, the AP news agency reported.

On Tuesday a 34-year-old delivery driver pleaded not guilty to 11 arson-related crimes by prosecutors in southern California.

Justin Wayne Halstenberg is alleged to have started one major wildfire - dubbed the Line Fire - which burned through 61 square miles (158 square kilometers) of the San Bernardino mountains east of Los Angeles.