Camp Williams Fire 2012 Maps: Wildfire Near Los Angeles Remains at Five Percent Containment; Four Are Injured (Timelapse Video)

The Williams Fire affecting the Angeles National Forest continued to remain at five percent containment on Tuesday, InciWeb reported.

The fire, which began on Sunday at around 2 p.m., has burned about 3,600 acres, reported CBS-affiliate KCAL. Nearly 800 firefighters were battling the blaze, InciWeb reported, along with 11 air tankers and 10 helicopters.

Officials told reporters that the area being burned had not been hit by fire in at least 15 years and that steep terrain and dry fuel could help the Williams Fire spread quickly.

The Los Angeles Times reported that full containment could not be reached until next Monday and would require crews to dig a fireproof strip of earth around the perimeter of the fire.

Angeles National Forest Officer Angie Lavell told the Los Angeles Times, "It's extremely steep and rugged terrain, and some of it is inaccessible. So it's going to take a very long time."

The cause of the fire is still under investigation, officials said. A burned car, rumored to be the cause, was being investigated as well, the Los Angeles Times said.

According to the Times, the Williams Fire forced officials to suggest evacuations for nearby residents and campers at Camp Williams Resort. CBS reported that the fire threatened no structures but that two park rangers and two campers had been injured.

The American Red Cross opened an evacuation center in Glendora, Calif. on Monday.

Williams Fire Maps

View Williams Fire in a larger map