Crews working in sweltering conditions and steep terrain battle major Los Angeles-area wildfire

GORMAN, Calif. (AP) — Strong winds pushed flames through dry brush in mountains along Interstate 5 north of Los Angeles, and officials warned residents in the wildfire's path to be prepared to leave if it explodes in size again.

Los Angeles County's first major wildfire of the year swiftly grew to nearly 23 square miles (60 square kilometers) on Sunday, one day after it forced the evacuation of at least 1,200 campers, off-roaders and hikers from the Hungry Valley recreation area.

The blaze, dubbed the Post Fire, was just 2% contained Sunday evening. No injuries were reported. The cause was under investigation.