Firefighters were battling at least two brush fires Sunday in unincorporated Alameda County, near Livermore, and some of the flames were blocking traffic on Highway 84.
One blaze, which Cal Fire reported to be 20 acres, was burning in the hills between Interstate 680 and Vallecitos Road, shutting down lanes on westbound 84 east of I-680, according to the California Highway Patrol.
That fire was 50 percent contained as of 6 p.m. Sunday.
Livermore Fire officials said two fires were burning in the area, and they had made forward progress on both as of 5:30 p.m.
The blazes were burning near Ruby Hill Golf Club, but no structures were threatened and no injuries were immediately reported, fire officials said.
The CHP issued a Sig-alert about 4:20 p.m.
The fire were under investigation.