Updated

Fire officials say about 25 additional homes were evacuated overnight, as a wildfire burning in a San Francisco Bay Area wilderness park grew.

The blaze in Mt. Diablo State Park in Contra Costa County has burned 1,500 acres as of Monday morning, up from about 800 acres the previous day when it broke out. The fire is 10 percent contained.

About 100 homes have been evacuated around the town of Clayton, about 35 miles northeast of San Francisco

State fire spokesman Dave Shew says hundreds of additional firefighters are expected to join the fight against the blaze Monday. He says he's confident the fire will be brought under control in a few days.