Washington, Sep 13 (IANS): Three inmates were killed and five others were injured in a riot that broke out at a private prison in Oklahoma state of the US, media reported on Sunday.

The about 40-minute riot took place on Saturday evening at Cimarron Correctional Facility in Cushing, Xinhua news agency reported.

Steve Owen, spokesman for Nashville-based Corrections Corporation of America which owns and operates the facility, confirmed the incident, saying that the riot was restricted to a single housing pod and the prison was placed on lockdown.

Owen, who did not disclose the reason behind the disturbance, said the injured inmates were sent to hospital for treatment while no prison staff member was injured.

The Cimarron Correctional Facility houses about 1,600 medium and maximum-security male inmates.

Similar incidents have taken place in the prison over the past years with the latest one in June this year in which 11 inmates were hospitalised after a fight among them from three housing units in the prison.