US forest service admits to starting New Mexico wildfire nearly the size of greater London

Extreme heat and dry weather make controlled burns difficult to execute

One of the two blazes in New Mexico that combined to become the largest wildfire in the state was started by the US Forest Service (USFS), the agency has admitted.

USFS said on Friday that the Calf Canyon fire started from a planned burn it set over the winter, but turned into a “sleeper fire,” that continued to smolder unnoticed.

It said the Calf Canyon Fire was caused by a “burn pile” of branches which the agency thought had burned out by 9 April, but later reignited ten days later on April 19 and escaped containment lines.