The so-called Olga Fire was reported at 11:42 a.m. in the area of Grape Lily Circle and Valle del Oro.
The blaze prompted a massive response from firefighters due to the number of homes threatened in a large residential area.
An unspecified number of houses and apartment units caught fire, though none were apparently destroyed. An assessment of the damage was ongoing Saturday afternoon.
Los Angeles County firefighters helped rescue several residents from inside an apartment complex, at least two of whom were injured. Their conditions were not immediately known.
The Olga Fire's forward progress was stopped about an hour after burning just under 1 acre. The cause of the fire is under investigation.
Meanwhile, the so-called Wiley Fire started about 12:30 p.m. near the intersection of Burton Way and Vasquez Canyon Road in Canyon Country.
Multiple agencies responded to fire, which was contained after scorching 3.6 acres. No injuries or structural damage was reported as a result of the Wiley Fire.