A fierce wildfire that has devoured drought parched terrain in Northern California with remarkable speed raged on for a sixth day on Monday as evacuations expanded and firefighters began to gain some ground against the flames

The blaze, dubbed the Rocky Fire, has scorched some 60,000 acres and destroyed two dozen homes since erupting last week in the canyons and foothills along the inland flanks of California's North Coast Ranges, quadrupling in size over the weekend.

The flames raced through 20,000 acres in one five-hour stretch on Saturday night, a growth rate that officials from the California Department of Forestry and Fire Prevention (Cal Fire), described as "unprecedented."