The John J. Moran Medium Security Facility in Cranston, Rhode Island, has been placed on lockdown pending a police investigation.
Prison spokesman Cory Cloud said on Wednesday that the facility was working with state police to investigate the situation.
Cloud said he couldn't comment further on the nature of the investigation. He didn't immediately know when the lockdown began.
Inmate visits have been suspended pending the investigation.
Cloud said there is no threat to public safety.