OKLAHOMA CITY -- Oklahoma City firefighters believe they are making progress in controlling a grass fire on the city's southeast side, but the fire is not out and residents are asked to leave their homes.

Battalion Chief Benny Fulkerson says the fire has burned about 1 square mile Sunday afternoon and homes along Southeast 164th between Air Depot and Midwest Boulevard should be evacuated.

Fulkerson says no injuries have been reported and no homes have been burned, although some outbuildings have burned. He said helicopters are being used to drop water on the flames.

Fulkerson said 60 to 70 Oklahoma City firefighters have been joined by about firefighters from about a dozen nearby departments to help fight the fire.