CAMP PENDLETON (CNS) - A brush fire charred open terrain at Camp Pendleton Monday, posing no structural threats and causing no reported injuries, authorities said.

Military firefighters monitored the blaze, which had blackened about 20 acres as of early afternoon, to make sure it didn't get out of control and move toward any developed areas at the North County Marine Corps station, according to base officials.

It was not immediately clear if the fire was sparked by ordnance or some other cause.