At least three spot fires sparked in Tierrasanta Thursday afternoon, sending heavy smoke into the air.
The brush fires began around 2:15 p.m. at Tierrasanta Boulevard and Rueda Road. San Diego Fire-Rescue officials said.
As of 2:30 p.m., fire crews were working to extinguish the fires, preparing water drops. By 2:40 p.m., the blazes had been knocked down, officials confirmed.
The cause of the fires is under investigation. No injuries were reported. Some homes south of the area where the fires started were evacuated as a precaution.
Arson investigators are looking into reports that three teenagers started the fires.