Four firefighters sustained minor injuries while fighting the enormous King fire burning in a forest region east of Sacramento.

The King fire, which broke out Saturday east of Pollock Pines, forced the evacuation of more than 1,600 homes by Wednesday and ballooned with new fury.

The blaze, which started September 13, in Eldorado National Forest grew to 81,944 acres and was 10% contained as of Saturday evening, said Cal Fire spokesman Scott McLean.

Nearly 5,100 firefighters were battling the fire, he said.

Nearly 3,000 people have been evacuated from the area, and 21,000 structures remain threatened by the blaze, which started Sept. 13.

Gov. Jerry Brown on Wednesday declared a state of emergency in El Dorado and Siskiyou counties because of the effects of the King and Boles fires. The latter fire, which destroyed 150 structures in Weed, had burned 375 acres and was 60 percent contained as of Wednesday night, according to the California Department Of Forestry and Fire Protection.

“The wildfires in Northern California serve as a reminder that dry conditions can be the precursor to devastating loss,” said Brown in his proclamation.

“We are faced with a large and dangerous fire, and the fire has grown significantly,” said Laurence Crabtree, U.S. Forest Service supervisor for the Eldorado National Forest. “We have had significant losses of public timberland, private timberland and watershed.”

The U.S. Forest Service is jointly managing firefighting efforts in the area, along with the California Department of Forestry and Fire Protection.

Higher humidity is expected to help control the spread of the blaze. On Saturday, ground crews worked to strengthen containment lines around the fire to prevent further spread of the fire.

Warm temperatures, low humidity and forests full of extremely dry trees, the result of serious drought conditions in the region, contributed to the fire’s severity, said Cal Fire spokeswoman Lynne Tolmachoff.

National Weather Service meteorologist Jason Clapp said that possible thunderstorms in the area late Saturday could pose a threat to firefighters by strengthening the fire. The meteorologists were also watching closely to see whether shifting weather patterns early next week would generate winds similar to those present last week when the fire spread quickly.