An attack at Auckland’s maximum security prison, which left one inmate needing surgery, is thought to be gang-related.
The attack happened in a cell of Paremoremo's B block just before 10am when four prisoners set upon the victim, stabbing him in the neck.
He was taken to North Shore Hospital with life-threatening injuries and later transported to Auckland City Hospital for surgery on a punctured lung.
A district health board spokeswoman said he was in a stable condition surgery this afternoon.
Police said the fight spilled on to the landing of the cell block where two other inmates got involved in the scrap and were also assaulted.
"Both victims received a beating and were stabbed with home-made weapons," police said.
Corrections officers broke up the fight and called emergency services.
After the most seriously injured was rushed to hospital, another man received 16 stitches for a wound to his arm.
The other victim was treated for bruises.
A police spokeswoman said officers had recovered three “shanks”, which had been used in the attack and officers were interviewing the quartet they believed were responsible.
She confirmed the bloody stoush was being treated as gang-related but would not say which particular gangs were thought to be involved.