The fire burning near Nobel and Towne Center drives was near train tracks and an apartment complex. AMTRAK officials halted train activity to allow firefighters to access the area.
San Diego Fire-Rescue spokesman Lee Swanson told FOX 5 that the University City fire had charred about an acre and they appear to be getting the "upper hand" soon after it sparked.
Swanson said the fire was initially estimated at one acre in size, but it grew somewhat as it burned up a hill toward an apartment complex. No structures were damaged by the fire.
Crews on the ground were assisted by two firefighting helicopters.
Crews are extinguishing a brush fire that has blackened about a quarter of an acre in an open area off Interstate 8, near Tavern Road in Alpine, according to Cal Fire. Firefighters have halted the spread of the flames, which posed no structural threat, according to the state agency.
No evacuations were ordered, according to Swanson. The cause of both fires were under investigation.