A central Auckland prison has been on lockdown since two guards were assaulted by a prisoner this morning.
A Department of Corrections spokeswoman said a prisoner from Mt Eden Corrections Facility had been placed in segregation following an "unprovoked assault" on two officers about 11.15am today.
Both staff members were punched by the prisoner and knocked to the ground.
Other staff moved quickly to bring the situation under control and both officers were taken to a medical centre for treatment and are now at home.
They are being provided with ongoing support.