CAL FIRE contains 35-acre grass fire in Contra Costa County, near Clayton

CONTRA COSTA COUNTY, Calif. (KGO) -- A 35-acre grass fire burning in Contra Costa County near Clayton is now 50% contained, CAL FIRE said just before 3 p.m. on Sunday.

The fire is burning near Kirker Pass Road and Nortonville Road near Clayton and Pittsburg.

CAL FIRE said the blaze started from a car fire and had a "moderate rate" of spread, but forward progress has been stopped.

Kirker Pass Road is closed from Hess Road in Concord to Buchanan Road in Pittsburg, the fire department said.

CAL FIRE said crews will remain at the scene for two to three hours.

This is developing, check back for updates