A wildfire burning Monday evening south of Peña Blanca Lake had grown to 400 acres and has the potential to spread quickly, officials said.
The Peña Fire, west of Nogales, was burning grass and brush on Coronado National Forest land.
There is a potential for rapid fire growth because of the gusty winds and low relative humidity. The area is under a red-flag warning until 7 p.m.
Multiple engines, fire crews and aircraft were being assigned to fight the blaze.