About 30 Corrections Department staff from Auckland called in sick for work on Sunday after "an increase in organised violence toward staff, orchestrated by gang members".
Department of Corrections Regional Commissioner Jeanette Burns said there had been five prison guards attacked by inmates in the last week alone.
The assaults typically involved punches to the head or upper body. Staff injuries include bruising and abrasions, she said.
"Over the last fortnight there has been an increase in organised violence toward staff, orchestrated by gang members at the prison," Burns said.
The Corrections Department said it brought in guards from other prisons because of "a higher than usual number of staff calling in sick", Stuff reported.
Corrections Association president Alan Whitley said at least 30 staff members from Paremoremo prison called in sick on Sunday.
On Saturday a Corrections staff member was assaulted, Stuff reported.
Department of Corrections Regional Commissioner Jeanette Burns told the Herald she was at the prison on Sunday and it was operating as usual.
"I have been on site at the prison today, along with the prison's management team, and the prison is largely operating as usual, with the assistance of staff from other prison sites.
On Friday a maximum security prisoner with gang affiliations attacked a Corrections Officer at the Auckland prison.
Burns said a staff member was giving the prisoner a mop and bucket to clean his cell when he punched the officer in the face without warning.
"Other staff reacted immediately to bring the incident under control, with the use of pepper spray, and the staff member was taken to hospital for medical assessment."
Last week there had been three staff assault incidents at the prison, she said.
"Last Friday, two staff were assaulted by a prisoner who was attempting to make an illegal phone call.
Burns said the ringleaders of the gang activity had been segregated to disrupt their influence and would be held to account.
"The prisoners responsible for the assaults on staff have also been segregated, and we are working with police to ensure that they are held to account through criminal prosecution," she said.
"These assaults are unacceptable. Our staff come to work every day to keep New Zealanders safe from the most violent and volatile prisoners that we manage. They do an exceptional and brave job in often very challenging circumstances.
"The assaults on them have been gutless and unprovoked."
Auckland Prison is New Zealand's only specialist maximum-security prison facility.