FORT MADISON, Iowa (AP) — An Iowa prison is restricting inmates’ movement in a housing unit after a staff member was assaulted.

Prison officials say the staff member was assaulted Saturday at the Iowa State Penitentiary in Fort Madison. The staff member was treated at Fort Madison Community Hospital and released. Authorities say visits to Housing Unit Two in the prison will be suspended until further notice.

Prison officials say the incident remains under investigation and released no other details.