A boy was treated at the school for a minor eye injury following the 1 p.m. incident in the school's south building, Deputy Police Chief Gregory Halstead said.
It wasn't immediately clear what ignited the melee, which the deputy chief said involved male students throwing punches and female students shouting at each other.
"From information gleaned to this point, the fight involved rival factions of some sort," he said Tuesday afternoon.
"The fight had already been contained by school security and staff upon police arrival and all parties involved had been separated," he said. "There were no reports of any weapons used."
School officials and members of the Englewood Police Youth Services Division were investigating.
Meanwhile, Halstead said, "all involved were asked not to return to the school for at least the next day until more facts are gathered."
Anyone with information that could help the investigation is asked to call the Dwight Morrow High School administrative office or the Englewood Police Department Youth Services Division at (201) 568-4713.
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