Firefighters from at least two agencies were working on a flareup that was spotted in the Holy Fire burn area, officials said.
The Cleveland National Forest twitter account said the flareup had escaped containment lines and has grown to 40 acres.
There was no other reports of new injuries or damage as a result of the flare up.
Orange County Fire Authority Capt. Tony Bommarito said five air tankers and four helicopters were assigned to the flare-up.
"Their objective will be to protect communication towers, but there are no residential structures threatened," Bommarito said.
The Holy Fire was officially contained on Sunday, but video from a stationary camera located on top of Santiago Peak near Trabuco Canyon showed massive plumes of smoke and high fires shortly after 10 a.m. on Monday.
The Holy Fire blackened an estimated 22,986 acres in Orange and Riverside counties, as well as damaged or destroyed 24 structures, officials said.
This is a developing story, more details will be added as they become available.