Three Hawke's Bay Regional Prison officers were attacked while they prepared an inmate for transfer to another facility - one of the officers requiring hospital treatment while a second was left with minor injuries which were treated at the scene.
The officer admitted to hospital was treated and discharged a short time time later.
Wednesday night's incident was the second explosion of violence at the prison in just four days and an investigation is underway by corrections staff and police.
Last Sunday two lots of prisoners, described as "opposing groups", clashed at the prison leaving several with minor injuries which were treated by medical staff.
The incident was sparked by what a Corrections spokesman said had been a disagreement which resulted in a series of skirmishes which lasted about 10 minutes. No corrections staff were injured on that occasion.
It is understood the inmate concerned in Wednesday's incident had been re-classified as a maximum security prisoner and was in the process of being readied for transport to a more suitable facility, and that there may have been a link to the violence on Sunday.
Within seconds of the prisoner lashing out several other staff ran to the aid of the officers and quickly had the situation under control - although the after-effects may linger.
Hawke's Bay Today understands that guards at the prison are becoming increasingly worried about their safety and that increased lock-down times has created tension.
Hawke's Bay Regional Prison manager George Massingham said staff safety was a priority and that Corrections took the issue of violence in prisons very seriously.
"Prisoners can be volatile and unpredictable and many have long histories of antisocial behaviour and resort to violence with little warning."
Violence would not be tolerated and prisoners involved would be "held to account for their actions."
Mr Massingham said initiatives to improve safety and security was ongoing, with recent initiatives involving introduction of pepper sprays to all prisons, increased tactical training and personal protective equipment for staff and the development of the 'Right Track' project.
He said frontline staff working in high risk situations were trained to use protective equipment like stab-proof vest, batons and spit hoods.
The concept of arming staff could likely be more hindering than beneficial, Mr Massingham said.
"The professional relationship between staff and prisoners is very important and should not be damaged through a perception of staff being armed," he said adding that officers were expected to use a range of tactical options to minimise the need to use force - such as tactical communication, de-escalation techniques and negotiation.
"Our staff work closely with prisoners by actively managing them and motivating them to make more positive decisions. The Right Track project is looking at the knowledge, behaviours, skills, tools and systems we need to encourage offenders to make good choices in their lives. This requires officers to encourage and role model acceptable behaviour to prisoners, listen to their concerns, help them solve problems and provide positive direction where necessary."
He said "positive interaction" between prisoners and staff resulted in potential problems being identified and resolved quickly.
"Therefore reducing the number of incidents occurring in prison."
But Mr Massingham made it clear that despite the efforts made to ensure risks were minimised there would continue to be occasions where violence and assaults would break out and staff would be injured.
"Despite our best intentions, we cannot prevent all assaults and no jurisdiction in the world has achieved this."
It was not known if the officers involved in the incident had access to pepper sprays - the matter was being investigated by police and Corrections were unable to make any further comment.
During a four-month period between July and October last year there were three violent clashes at the prison with two of the incidents resulting in officers sustaining injuries.
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