BISHOPVILLE, S.C. (WACH, AP) -- South Carolina Corrections Department spokesman Clark Newsom says officers rescued a prison guard and regained control of the building at the Lee Correctional Institution in Bishopville shortly after 3 a.m. Wednesday.

Communications Director Clark Newsom said a nurse escorted by a guard was passing out medication in the Sumter unit of Lee Correctional Institute around 9 p.m. Tuesday when a group of inmates overpowered the guard. Newsome did not know how many inmates were involved, but the unit houses as many as 130 inmates in the high security prison.

Newsom said the nurse escaped. He said the guard may have been carrying either Mace or a baton, but no firearms; which is standard procedure when distributing medication.

He says about 100 officers blew open a door and rescued the guard after discussions with the inmates failed to resolve the situation. Newsom said the inmates tried to disguise the guard as an inmate by changing his uniform.

The guard was taken to a hospital and released later. He suffered only a minor injury to his head.

Newsom said the investigation is ongoing, but there may be a clue as to why it happened.

"It is hard to determine. They voiced a few concerns. They have a new warden there. Whenever you have a new warden, a lot of times new policies will go in place. That can be upsetting to some of them. It never seemed to be a consistent story in what they were looking for. And that was concerning to us."

According to Newsom, the inmates involved will face more charges and will likely be moved to other facilities.

The Associated Press contributed to this report.