Thousands of firefighting personnel were battling early on Friday a wholly uncontained wildfire spread over some 51,000 acres in the steep mountains north of Los Angeles.

Weather conditions have given firefighters a better chance of preventing more damage from the blazes that have displaced tens of thousands of residents.

On Friday, containment of the 51,884-acre Bridge fire increased to 3% after days of marching its way north over the Angeles and San Bernardino National forests.