Several inmates were injured in a fight after 36 cell doors were accidentally opened Tuesday morning at Scotland Correctional Institute, according to a state prison official.

A prison guard mistakenly opened all the doors in two cellblocks at the medium-security facility, according to Keith Acree, spokesman for the state Department of Correction.

"At this point it appears to be human error," Acree said.

Acree said several inmates came out of the cells and began fighting. Acree said that "shanks" – makeshift knives – were used by some inmates.

Three inmates were treated for minor cuts. There were no reports of prison officials being injured.

Acree said at no point was there a risk that an inmate would escape. He said the doors are sealed between each cellblock and each block is divided into two floors, nine cells on each, that are also blocked off.

Prison officials said they were able to restore order within an hour of the doors being opened.

Acree said none of the inmates have been charged and that the sheriff's office will investigate the incident.

DOC administrators will review the situation to determine how to prevent future incidents.