Sept. 10, 2015: In this photo a home burns near Mokelumne Hill, in Jackson, Calif. (Andrew Sent/The Sacramento Bee via AP)

Hundreds of people were forced to evacuated on Friday as a Northern California wildfire threatened rural communities, destroying six homes, threatening thousands more and prompting the governor to declare a state of emergency.

"It's expanding like a balloon," state fire spokeswoman Nancy Longmore said. "It's moving very fast. There's many homes threatened. ... This fire is extremely dangerous."

The slow-moving fire managed to burn about a single square mile on Thursday. However, the fire exploded, burning 101 square miles by Friday evening. It was only 5 percent contained.

At one point, the blaze was bearing down on the 2,700 residents of San Andreas, prompting an evacuation order for the entire town 60 miles east of Sacramento. However, the fire would change direction, and the order was called off a short time later, state fire spokesman Daniel Berlant said.

"The fire was quickly approaching the community," Berlant said. "This fire is very dynamic and changing different directions with the topography. ... That makes it very unpredictable, and with the exponential growth, we're seeing a lot of danger not only to residents in the path of this fire but to our own firefighters, as well."

San Andreas residents were still told to prepare to leave just in case the fire turned around again. At least 460 residents from surrounding towns were under evacuation order and moved to evacuation centers for the night.

One of those evacuation centers was at the San Andreas Town Hall, which itself had to be evacuated for a while. "I had to move a kitchen full of food, 217 beds, three huge air conditioners," said Gina Gonzales, a Red Cross volunteer organizing the evacuation center.

About 90 minutes after moving everything to the Calaveras County Fairgrounds, Cal Fire ordered the evacuation center to move back to the San Andreas Town Hall because firefighters were planning on making the fairgrounds their base camp, Gonzales said.

The lack of communication being given to the evacuees angered some residents, she said.

 Six homes and two outbuildings burned Thursday, and 6,000 more were threatened, Longmore said. The number of homes burned could increase, as Longmore said the blaze was moving through rural areas with houses.

"The plan is to try to get this thing out," she said. "It's going to take quite a bit of work. We're in for the long haul here."

Gov. Jerry Brown declared a state of emergency, helping to free up funding and resources in the firefight.

More than 1,500 firefighters, 178 engines and seven air tankers and 16 helicopters were dispatched to fight the fire, which began Tuesday. The cause of the fire is still under investigation.

Meanwhile another California wildfire threatened to sweep through an ancient grove of Giant Sequoia trees. The lightning-caused fire has charred 172 square miles and grew by nearly 40 square miles in the last week.

In a fight to save the trees, firefighters have been clearing lines with bulldozers around the Grant Grove and putting up sprinklers, said Andy Isolano, a spokesman for the Clovis Fire Department.

The grove is named for the towering General Grant tree that stands 268 feet tall. There are dozens of Sequoia groves in the Sierra Nevada, and some trees are 3,000 years old.

Fresno County Sheriff's deputies were going door to door Friday distributing mandatory evacuation notices to residents in the tiny community of Dunlap, east of Fresno. About 130 people live in Dunlap, but it wasn't clear how many residents will need to leave.

On Thursday, officials from Kings Canyon National Park ordered the evacuation of all Sequoia National Forest park visitors and park employees, concession staff and residents of Wilsonia in the Grant Grove area of the park.

The Associated Press contributed to this report.