Drone video released Saturday showed plumes of smoke emanating from a warehouse east of downtown Los Angeles as firefighters battled the sprawling blaze for a third day. Image courtesy Los Angeles Fire Department/Facebook

June 21 (UPI) -- Firefighters battling a massive fire at a Los Angeles warehouse that has darkened skies around the city cited progress against the smoldering blaze in an update issued Sunday.

The fire, which broke out Wednesday in the Boyle Heights neighborhood just east of downtown Los Angeles, caused smoke to blanket the surrounding area and prompted an emergency declaration from Mayor Karen Bass.

Her declaration triggered the opening of 24-hour-per-day smoke relief centers for residents who could not shelter-in-place as officials urged those in the area to stay inside and avoid strenuous activities.

California Gov. Gavin Newsom also declared an emergency over the "Palos Fire" as drone videos released by the Los Angeles Fire Department showed the extensive scope of the blaze consuming a 500,000-square-foot cold storage warehouse.