Firefighters were slowly making progress in their battle to contain the inferno that has razed swathes of Los Angeles' Pacific Palisades neighborhood to the ground, but still-spreading flames threatened communities in the populous San Fernando Valley on Sunday.

A number of videos have been shared on social media showing the Palisades fire, the most destructive in Los Angeles' history, making its way toward the populated San Fernando Valley with mandatory evacuation orders in place.

It was initially reported as an arrest made on the suspicion of arson, with Sean Dinse of the LAPD’s Topanga Division telling a NewsNation reporter on Thursday night that the authorities believed someone had purposefully set the Kenneth Fire.

Authorities said there was not enough probable cause to arrest the man on suspicion of arson, but he has been charged with a felony probation violation

Everything we know about ‘armed’ arson suspect arrested near Kenneth blaze as LA wildfires rage - LAPD believe the Kenneth fire was started intentionally after breaking out on Thursday, with Palisades and Eaton fires still burning,