Four inmates at an Oklahoma prison are dead after several stabbings that reportedly happened in quick succession while the prisoners were being let out into an exercise yard.
The incident occurred at around 4pm on Saturday at the Cimaron Correctional Facility, a prison located about 75 miles northwest of Oklahoma City. The facility is operated by the Corrections Corporation of America (CCA), a Tennessee-based company.
"Yesterday's inmate-on-inmate altercation lasted less than two minutes with staff responding very quickly to quell the disturbance," a CCA spokesman said in a statement. "Staff then worked for approximately 38 minutes to secure the housing area where the incident took place."
Prison officials told KOCO-TV that the violence affected only one housing unit in the prison, and that a guard in the unit at the time was unharmed.
"The entire stabbing incident happened over a couple of minutes," Terri Watkins, a spokeswoman for the Oklahoma Department of Corrections, told the Associated Press.
Three inmates were killed during the melee, and and least five others were hospitalized with injuries. The fourth prisoner died overnight in the hospital from his wounds. CCA said the remaining injured inmates are in stable condition, with at least one well enough to return to prison on Sunday, according to the AP. The identities of those injured or killed have not been released to the public.
The prison, located in Cushing, Oklahoma, houses around 1,600 medium- and maximum-security male inmates.
The prison has remained on lockdown since the attack, and Watkins said all Oklahoma prisons have also been put on lockdown as a precautionary measure. Two separate investigations — one by the Department of Corrections' inspector general's office and the other by CCA — are reportedly underway.
This is the second major violent incident at the prison in the last four months. Eleven prisoners were injured in June during a brawl that involved more than 200 inmates, according to the AP.