SPRINGFIELD — South Dakota corrections officials say they are investigating a pair of incidents at the state prison in Springfield that left six inmates injured.

Department of Corrections spokesman Michael Winder said fighting began Tuesday night at the Mike Durfee State Prison, followed by another incident Wednesday morning. The six inmates suffered non-life-threatening injuries, he said.

Winder also said some prison staff suffered minor injuries while restoring order, but there were no assaults or damage.

Shouting through fencing and open windows, inmates at the converted college campus on Wednesday expressed their frustrations to reporters.They said they had been locked down and weren’t allowed to make phone calls to their families since the fighting broke out. Their complaints included gang activity, understaffing and the lack of air conditioning in their cells.

In March, at least one correctional officer was injured in a disturbance at the State Penitentiary in Sioux Falls.