A cooking fire at a homeless camp ignited the wildfire that threatened the affluent Los Angeles neighbourhood of Bel Air, officials have said. [restrict]

“Investigators have determined the fire was caused by an illegal cooking fire at an encampment in a brush area adjacent,” the Los Angeles Fire Department said in a statement, adding that no arrests had yet been made in connection with the fire.

While not as large as the two other blazes that scorched thousands of acres in Los Angeles County, the Skirball Fire attracted attention as it imperilled upscale homes and the Getty Center, feeding on dry brush in the hills.

After roaring to life on Wednesday morning, the blaze consumed hundreds of acres, incinerated six structures and damaged a dozen others. Los Angeles residents shared apocalyptic images of hills cupping the city engulfed in flames.

Firefighters had the fire 85 percent contained as of Monday evening, and residents who earlier faced mandatory evacuations had begun returning to their homes days earlier.

Two fires that had collectively burned across thousands of acres in northern Los Angeles County were also largely under control, as was a conflagration that had roasted some 4,100 acres in San Diego County.

But the massive Thomas Fire continued to burn across a wide swathe of Ventura County and Santa Barbara County, where thousands of people have been forced from their homes and nearly 800 structures have crumbled in the flames. Flames have consumed some 234,000 acres.

In its latest update, Cal Fire warned that “severe fire weather” conditions of gusty Santa Ana winds, low humidity and parched vegetation would continue to feed the inferno and create obstacles for firefighters struggling to curb it.

“Extreme fire behaviour will continue to hamper control efforts,” the alert warned. /[restrict]