Four firefighters have been injured — one seriously — battling a blaze that threatens 150 Northern California homes.

Fire spokesman Daniel Berlant says two state firefighters and two U.S. Forest Service members were injured around 5 p.m. Sunday in the 2-square-mile blaze in Nevada County.

Three are expected to be treated and released. Berlant says the fourth has injuries that are serious but not life-threatening.

The fire in Sierra Nevada foothills is 15 percent contained and burning in heavy, drought-stricken timber.

Some 40 scattered rural homes are under mandatory evacuation but Berlant says up to 200 are considered at risk. He says there's concern the winds will shift on Monday and drive the flames back south.

Berlant says in that case, hundreds of additional homes could be threatened.