Thousands of Southern California residents fled their homes Thursday as a wildfire continues to burn through a mountainous region some 100 miles east of Los Angeles. According to the Associated Press, more than 6,000 people in the Idyllwild area have been ordered to evacuate their homes, though some continue to stay at home throughout the fires.

The so-called Idyllwild fire started on Monday afternoon, possibly from arson, the Los Angeles Times reports. The fire grew rapidly over the past two days, consuming over 35 square miles of land in Southern California’s San Jacino Mountains. The fire is rapidly spreading throughout the San Bernardino National Forest, heading towards the nearby towns of Idyllwild, Fern Valley and Palm Springs.

Officials in the area say the Idyllwild fire is only 15 percent contained at the moment, though a team of more than 3,000 firefighters are working to slow the blazes down. Reuters reports that 17 water-dropping helicopters and 10 air tankers have also been assigned to slow the fire’s approach.

Unusually, the wildfire has been growing at night as well as during the day. Typically, wildfires dwindle somewhat during the night as temperatures cool down.

"Usually it cools down at night and we get more humidity. That hasn't happened," Tina Rose, a spokeswoman for the California Department of Forestry and Fire Protection, told the Associated Press. "It's been burning like it's daytime for 72 hours in a row."

The thickly forested wilderness surrounding Idyllwild has not burned in several decades, which could have led to large amounts of overgrowth that may be fueling the Idyllwild fire’s unusual growth.

Flames of the Idyllwild fire are reportedly burning as high as 100 feet at some spots. At this writing, more than 4,100 structures, included homes, hotels, and rental properties, are threatened by the approaching wildfire. No injuries have been reported.