Hundreds of firefighters scrambled Monday to prevent a wildfire engulfing an area of rare giant sequoia trees in California's Yosemite National Park. The Washburn fire, in the Mariposa Grove of giant sequoias, was first reported on July 7 and doubled in size over the weekend to 2,340 acres (946 hectares), according to a park report. Yosemite's fire management service said 545 firefighters were battling the blaze, including "proactively protecting" the grove—the largest sequoia grove in Yosemite, with over 500 mature trees.

Further reinforcements were due to be deployed Monday, as the blaze remained out of control with increasingly hot and dry weather forecast, Nancy Phillipe, spokeswoman for Yosemite Fire Information, told AFP.

"It's still showing zero percent containment," Phillipe said.

"We are doing everything we can to put this fire out," including deploying air tankers and helicopters along with ground crews, she added.

See omnystudio.com/listener for privacy information.