A wildfire that erupted Friday in San Diego County just north of the U.S.-Mexico border remained at 25 percent containment Saturday.

The fire began spreading for unknown reasons through heavy vegetation near Campo and Marron Valley roads in the Dulzura area shortly before 4:30 a.m. Friday, according to Cal Fire.

The fire’s spread was halted by firefighters by early afternoon Friday.

As of 7 a.m. Saturday, the blaze had blackened an estimated 130 acres, according to the state agency.

Saturday, 150 personnel were battling the flames on the ground and aboard air tankers and water-dropping helicopters, said Isaac Sanchez of Cal Fire San Diego. That number is down from 220 firefighters on Friday.

Ten fire engines, six hand crews, four water tankers and a helicopter were involved in fighting the blaze.

While helping douse the fire Friday, a Cal Fire helicopter pilot made a safe precautionary landing in a nearby field. The cause of the unplanned grounding was under investigation, Sanchez said.

The cause of the fire was also unknown and under investigation.

—City News Service