Marine Corps officials say all nonessential staff have been ordered to leave Camp Pendleton because of a third wildfire that has ignited on the base.

The Marines say the new blaze cropped up Friday in the northwest section of the sprawling coastal base between Los Angeles and San Diego, prompting evacuations of military housing and an infantry school.

Officials say two others fires prompted the evacuations of 356 military families.

One fire on the base that broke out Thursday grew overnight from 600 acres to 8,000. That's 12 1/2 square miles.

The other fire sparked Wednesday on the eastern outskirts of the Marine base scorched nearly 10 square miles of dry brush.