UPDATE: Massive Brush Fire South Of Valley Continues To Grow

Added firefighters joined the fight Sunday, to contain a brush fire burning through the northeastern part of San Diego County.

The blaze has already burned some 11,000 acres since it first sparked on Thursday on the Los Coyotes Indian Reservation, near Warner Springs.

More than 1,100 firefighters, battling from the ground and in the air, were able to bring containment up to 40% by Sunday night.

“It is still actively growing,” California Department of Forestry & Fire Protection spokeswoman Julie Hutchinson said, “but in a slow way, without extremes in heat and wind.”

Smoke from the blaze could be seen hovering in the air towards the south end of the Coachella Valley, but fire officials say residents have no need to worry.

Cal-Fire said the cause of the fire remains under investigation.