CUSHING, Oklahoma - Three inmates are dead and five have been hospitalized after a riot at the Cushing prison, officials say.

The fight at the Cimarron Correctional Facility took place about 4:30 p.m. on Saturday, according to the facility’s private operator, Corrections Corporation of America.

The company provided News On 6 with a statement saying the deadly riot was in a single housing pod and lasted about 40 minutes. It did not provide any other information about the origin of what a spokesperson referred to as an "inmate disturbance" in a news release.

Officials say the prison is on lockdown so management and law enforcement have the opportunity “to isolate, review and investigate the incident, as well as conduct a welfare check on all offenders housed at the facility.”

The identities of the dead and injured inmates are pending release upon notification of next of kin. Medium- and maximum-security inmates are held at the 1,720-bed Cushing prison.

An investigation into the killings has been opened.

In June of this year, we reported on another riot there that hospitalized 12 inmates. Multiple units from the Payne County Sheriff's office and the Oklahoma Highway Patrol were called in to help get that situation under control in about an hour.