(CNN) -- One firefighter was injured during the night while battling wildfires that are causing evacuations in Northern California, a fire official said Monday.
Two fires were burning, affecting about 5,000 acres, according to Julie Hutchinson of the California Department of Forestry and Fire Protection. She said the fires started about the same time Sunday.
Hutchinson didn't have an update on the medical status of the firefighter injured.
Three subdivisions are under mandatory evacuation orders, including 480 homes in Long Valley and Spring Valley in Lake County.
The larger of the two fires -- 3,000 acres -- threatens those communities and has destroyed three buildings already. The fire is 25% contained, Hutchinson said.
The other fire -- burning not far away along the same road, California State Highway 20 -- is 2,000 acres, causing fire officials to order to order people in Wilbur Hot Springs to leave. The fire is 30% contained.
Officials say the fires likely will stay separated.
About 320 fire personnel were fighting the fires, Hutchinson said.
CNN's Greg Morrison contributed to this report.