A union says an attack on a prison officer at a Northland prison facility which left them with significant facial injuries is not an isolated incident.
The Corrections Association of NZ understands officers at the Kahu Unit at Ngawha Prison were unlocking prisoners from cells when the "unprovoked attack" occurred.
According to the Association, the officer was left with a dislocated jaw, broken and dislocated teeth and possibly a broken nose.
The Association said the attack happened about 10.55am on Saturday morning.
Prison staff were conducting a routine check on prisoners. When they opened the cell door, the prisoner was standing at the door and punched the corrections officer multiple times directly in the face without warning.
The officer's colleague called for help and some nearby prisoners kept the attacker away and gave their own clothing to help with the bleeding.
Association vice president Paul Dennehy said this was not an isolated incident, with figures released under the Official Information Act obtained by the union showing violent attacks are increasing.
"Assaults on staff across the whole country have been on the rise for several years," he said.
He was not sure of staffing levels at the prison when the incident took place, but he said understaffing is an issue at prisons around the country.
Dennehy said many attacks on staff were unprovoked.
"We don't know it's going to happen. We could be talking with a prisoner, the next thing that prisoner or another prisoner blindsides us and attacks, we've got no way of mitigating or defending ourselves immediately."
The association has pushed for prisoners to be held accountable for their actions that go against the rules
"They should be held accountable. But increasingly, we're finding that's not the case. They can be non-compliant, they can be assaultive, they can be verbally threatening, they can be physically attacking us. There are very few legal consequence, within the prison or with police charging them," Dennehy said.
"We work very hard to help rehabilitate prisoners, because one day they are going to be our neighbours."
Northland Region Corrections Facility prison director, Michael Rongo, said the attack was "unprovoked and cowardly".
Rongo said other Corrections officers responded quickly to bring the situation under control and the prisoner was initially moved to the prison's management unit.
"He has since been transferred to Auckland Prison to be managed as a maximum security prisoner. Police have been advised and will determine any criminal charges being laid against the prisoner," he said.
The officer who was assaulted received treatment from on site health staff and was taken to hospital for further treatment. Rongo said he and his family are receiving ongoing support.
A review has been commissioned into the assault.
"No assault or violent behaviour is tolerated, and any prisoner who resorts to this behaviour will be held to account, which can include police charges."
Rongo said there were no staff shortages at the prison and unprovoked attacks can happen at any time.
"As you will appreciate, we manage some of New Zealand's most dangerous people in an environment that can be complex and challenging.
"While Corrections considers no assault to be acceptable, we acknowledge the reality that these incidents do occur. Over 75 percent of the prison population have convictions for violence in their offending histories, and gang members are disproportionately identified as responsible for assaults in prison.
"Our staff recognise the importance of knowing and understanding people in prison, and actively engage with them to reinforce positive behaviour. We have invested significantly in training and tools to keep our people safe. This includes tactical skills, such as de-escalation, through to the introduction of stab resistant body armour, on body cameras and the expanded deployment of pepper spray.
Corrections said there were 18 serious assaults on staff in prisons in the 2019-2020 financial year.