Agency spokesman J.R. Ventura said Monday that the altercation occurred within the maximum security section at the Adult Correctional Institutions in Cranston.
He says one inmate was taken to the hospital to be treated for what appears to be a stab wound and he was conscious and responsive. The other inmate is being questioned.
Guards in tactical gear could be seen outside the prison Monday morning.
Ventura says the facility was put on lockdown to make sure the area is secured and safety protocols were activated as part of the normal response procedures.
He says it appears to be an isolated incident and an investigation is underway.
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