The N.C. Department of Public Safety says the riot occurred around 2:15 p.m. on Monday at Piedmont Correctional Institution in Salisbury and involved inmates fighting each other.
Department spokesman John M.R. Bull says none of the prison staff was injured.
According to Bull, nine inmates were taken for outside medical attention. Eight were treated and returned to the prison, and one was hospitalized for what he described as apparent non-life threatening injuries.
Bull said the prison remains on lockdown and authorities haven't said when it will be lifted.
The prison is conducting an investigation into what happened, who participated and the motive. Bull said his department will cooperate with Salisbury police in any investigation.
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