Commissioner Taitosauā Edward Winterstein said inmates ambushed the prison guards and assaulted them, leaving one in a critical condition.
Mr Winterstein told a news conference the five guards were overpowered by 36 inmates.
Earlier, it was reported that 29 had escaped but the news conference was told it was 36.
The guards received a range of injuries, and were treated at the Motootua hospital.
The prisoners then damaged the administration block, switched off communications and the power supply, and fled into the night.
