The Nebraska State Penitentiary was still locked down on Tuesday, following a Saturday altercation.
Visits and volunteer events have been canceled, according to a news release from Warden Dennis Bakewell.
The lockdown stems from an inmate-on-inmate assault in a housing unit, the release states.
Prison staff intervened, and the inmates were given medical care, Bakewell said. Their names were not released.
"The penitentiary continues on lockdown status," Bakewell's assistant, Win Barber, said in an e-mail late Tuesday. "The investigation is continuing and staff are assessing the situation."