California firefighters continued to battle the explosive Oak Fire near Yosemite National Park on Monday as what has become one of the state's largest wildfires of the year burned out of control and forced thousands to evacuate their homes.

The blaze has scorched over 15,600 acres – more than 22 square miles of forest land – as of Sunday, with no containment, Cal Fire said.

Evacuations were in place for over 6,000 people living across a several-mile span of the sparsely populated area in the Sierra Nevada foothills, though a handful of residents defied the orders and stayed behind, said Adrienne Freeman with the U.S. Forest Service.

"We urge people to evacuate when told," she said. "This fire is moving very fast."

YOSEMITE NATIONAL PAR WILDFIRES EXPLODE IN SIZE, US TAKES EMERGENCY ACTION TO SAVE SEQUOIAS

Since the fire erupted Friday southwest of the park near the town of Midpines in Mariposa County, flames have destroyed at least 10 residential and commercial structures and damaged five others, Cal Fire said. 

More than 2,500 personnel, nearly 300 fire engines and 17 helicopters have been dispatched to battle the blaze, according to Cal Fire.

Burned pickup truck and forest land

The Oak Fire burns behind a scorched pickup truck in the Jerseydale community of Mariposa County, Calif., early Sunday. (AP Photo/Noah Berger)

Firefighters "made good headway" on Sunday, officials said, with strike teams holding the fire at Bear Clover Lane to protect the Mariposa Pines community and working to hold other lines around the wildfire.

Firefighter standing on top of fire truck

A firefighter stands atop a fire engine shortly after coming on duty to battle the Oak Fire in the Jerseydale community of Mariposa County, Calif., on Sunday. (AP Photo/Noah Berger)

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The Oak Fire was sparked as firefighters made progress against an earlier blaze, the Washburn Fire, that burned to the edge of a grove of giant sequoias in the southernmost part of Yosemite National Park. The 7.5-square-mile fire was nearly 80% contained after burning for two weeks and moving into the Sierra National Forest.

The Associated Press contributed to this report.