The US Department of Agriculture (USDA) said the so-called Ferguson fire had spread to an area of 22,892 acres (92.6 square kilometres), and is so far only 7% contained.

More than 2,700 people are tackling the blaze, which started a week ago in the Sierra Nevada forest. Currently, there is no prediction as to when it will be completely contained.

Two firefighters were injured days after their colleague Braden Varney, 36, was killed while fighting the fire.

The fire has been fuelled by dead trees ― 27 million have died in the last year, and 62 million the year before after years of drought ― as well as leaves and grass dried out by the heat.

Evacuations were ordered in several communities, and in other areas the state fire agency Calfire advised residents to prepare to flee with scorching temperatures expected in coming days.

The fierce blaze has also forced the closure of a motorway and one of the entrances into Yosemite, famed for its ancient giant sequoia trees.

Along with California, the states of Alaska, Colorado and Oregon have suffered the highest numbers of fires.

However, the season has begun with less force than last year’s, which saw unprecedented blazes devastate California homes in Santa Barbara and Napa Valley wine country, leaving some 40 people dead.