Firefighters were battling a brush fire near homes in the hills above Gilroy late Sunday.
The blaze was first reported just before 8 p.m. at 1980 Ballybunion Court and had spread to at least 10 acres. By 10 p.m., the fire was estimated to be at least 50 acres.
No injuries were reported, and no homes or other structures were damaged late Sunday night, fire officials said. But with all the dry brush and vegetation in the area, neighbors were concerned.
"Our house is right up side along the grass, so we just immediately pulled our cars out and took them to my brother's house, just in case," said Alex Salinas, who lives just below the flames. "Then, get the hose ready."
Witnesses said the fire likely was caused by kids lighting off fireworks, but fire officials did not confirm the cause of the blaze.
The Gilroy Fire Department was being assisted by Cal Fire, San Jose, Mountain View and Santa Clara County fire crews.
No further details were available.