Firefighters were battling two blazes sparked by lightning Tuesday night in the Mendocino National Forest, officials said.

The Skeleton fire, about 6 miles east of Lake Pillsbury in the Snow Mountain Wilderness, had covered about 20 acres, the U.S. Forest Service said in a press release. The fire was moving at a “moderate rate” through chaparral, timber and grass. The Slides 2 fire was burning about 4 miles west of Lake Pillsbury, the release said. It did not detail the size of the fire. Other fires caused by lightning will likely be discovered after thunderstorms pass over, it said. Light northeast winds were blowing about 5 mph.

The fire information line is 530-640-1168.