An apocalyptic cloud of smoke from the brush fire raging in Azusa, California, towers over homes on Thursday evening (Aug 13).

Residents were evacuated as the blaze, dubbed the Ranch Fire, spread across 3,000 acres towards nearby properties.

Terrifying footage from one neighbour shows the glowing inferno ripping through the hillside at the start of the fire shortly after 3pm in the afternoon, when it was covering around 600 acres.

The Azusa Police Department ordered the evacuation of people in the Mountain Cove neighbourhood.

There was no reported structure damage as the fire was moving towards the forest areas and away from residences. According to the fire department, over 2,500 acres were burnt at about 6 PM.

The Los Angeles County Fire Department said the blaze was first seen around the North San Gabriel Canyon Road and North Ranch Road where it ''immediately threatened homes''.

The Azusa Police Department said residents of Mountain Cove were asked to evacuate immediately, and no traffic is being allowed into the area.

Authorities said that by evening it was burning away from foothill cities and towards Angeles National Forest.