A fourth inmate has died after a disturbance at a private Oklahoma prison, officials said Sunday.

The inmate, one of five injured in the the attack or fight at the Cimarron Correction Facility in Cushing Saturday afternoon, died overnight, Terri Watkins, a spokeswoman for the Oklahoma Department of Corrections.

The other three inmates who died were fatally stabbed, Watkins said. She did know the nature of the injuries to any of the other inmates, including the fourth who died.

Three injured inmates remained hospitalized Sunday and the fourth has been returned to the prison.

Prison staff quelled the disturbance around 4:40 p.m. Saturday, Steve Owen, a spokesman for the Nashville, Tennessee-based Corrections Corporation of America, said. The incident lasted about 40 minutes and was contained to one housing pod, he said.

None of the staff were injured. The names of those killed and injured were not immediately released.

The prison was placed on lockdown and inmates were confined to their housing areas, Owen said. The facility is about 50 miles southwest of Tulsa and houses medium- and maximum-security male inmates for the Oklahoma Department of Corrections.

The Tulsa World reports a welfare check was also conducted on all of the prisoners in the facility and the local law enforcement along with the Oklahoma Department of Corrections were immediately notified of the incident.

The incident occurred in the medium-security part of the prison,Watkins told The Associated Press. The prison is home to about 1,600 inmates.

Corrections Corporation of America, one of nation's largest private prison companies, has contracts with various states and other entities to house inmates.

The same facility had a separate incident in the beginning of the summer. Inmates from three housing units got into a brawl that sent 11 of them to the hospital, according to the Tulsa World.

In March 2013, there was a unit-wide fight that ended with windows smashed, security doors being breached and led to inmates being pepper sprayed after they made weapons from destroyed property, according to the newspaper.

Click for more from the Tulsa World.

The Associated Press contributed to this report.