California Department of Forestry and Fire Protection (Cal Fire) Battalion Chief Jon Heggie said the fire "is moving extremely fast and the reaction time to get people out is limited because that fire is moving so fast."
The official added that over 2 500 firefighters are battling the blaze, which has a "truly unprecedented" rate of advance and behavior.
In addition, Cal Fire said 17 helicopters, 281 fire engines, 66 bulldozers and 46 tankers had been assigned to fight the fire.
Firefighters are continuing to battle California's largest wildfire of the summer, a blaze near Yosemite National Park that has forced thousands of people to evacuate. The Oak Fire comes as parts of the US remain in the grip of a sweltering heat wave. | via AFP #DailyTribunepic.twitter.com/gqUQIihujQ
The "Oak Fire" spreads through Mariposa County, near Yosemite National Park and its famous giant sequoias. Seven structures have been confirmed destroyed, the agency said Monday.
The Cal Fire Battalion Chief called the disaster a "direct result of climate change" and said the fire was fueled in particular by dead trees and dry brush in a region that has long suffered from drought.
A press release from California Governor Gavin Newsom's office on Saturday said at least 3 000 people had been forced to evacuate their homes due to the fire.