STILLWATER, Minn. - State corrections officials are investigating an altercation that left four workers injured at the Stillwater prison.

Minnesota Department of Corrections spokesman John Schadl told the St. Paul Pioneer Press that a prison guard and one contract employee were taken to a local hospital Wednesday after the incident. Both were later released.

Schadl says two additional employees suffered minor injuries and did not require hospital treatment.

The DOC is releasing few details as the department is conducting an "active investigation," but Schadal did tell the Pioneer Press it did not appear that the incident was a riot or something that involved a large number of inmates.

"It may have been just one inmate responsible," Schadl said.

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