The blaze broke out on Tuesday in a mountain pass and has engulfed about 15,000 acres (6,070 ha) of land.

Thousands of homes are at risk from the so-called Bluecut fire. A state of emergency had been declared. Another fire, the Clayton, which broke out on Saturday in northern California, had already destroyed 175 homes.

The Bluecut fire spread with great speed in the parched canyons around San Bernardino. A dozen of buildings have already been engulfed. US Forest Service spokeswoman Lyn Sieliet said, "It is a very fast-moving fire, it has wind behind it.” California Governor Jerry Brown has declared a state of emergency in San Bernardino County to bring in federal assistance.

The blaze forced the closure of a stretch of Interstate 15, the main road between Las Vegas and Los Angeles area. Some 700 firefighters had been battling to control the blaze in the Cajon Pass. Its cause remains unknown.

By Prakriti Neogi