A new wildfire has ignited in the mountains northeast of Tucson.
Officials said the fire started near Redington Road in the Catalina mountains, about five miles outside of the city, around 2 p.m.
Information from the U.S. Forest Service said the fire was 750 acres as of Sunday evening and burning a mix of grass and brush.
Firefighters said a total of 75 people, including three helicopters and several air tankers, were on scene.
There was no immediate word on if any structures had been destroyed or were threatened by the flames.
Fire officials said the Racetrack Fire is believed to be human-caused, though investigators were still working on the exact specifics of how it sparked.