A woman was admitted to hospital after being savagely attacked by two dogs who tore chunks of flesh from her arm.
Animal Control staff have one of the dogs but police said the animals' owner has hidden the other.
The 54-year-old victim was walking towards Kawakawa township in a residential street when the attack occurred on the footpath at 11am on Monday.
Sergeant Kevin Milne said the two unrestrained dogs came out of a residential property that was not fenced.
One dog had grabbed her hand and held on while the other had attacked her upper body.
"The dogs then dragged her down on to the ground and continued the attack," he said.
It was unclear what breed the dogs were but they were described as brown medium-build cross-breeds.
The owner of the dogs had run to help the woman and the dogs had obeyed when he told them to stop. She was then driven to Bay of Islands Hospital by the owner and a neighbour.
By that time she had sustained injuries to her hand and upper arm.
"It wasn't just the teeth that had gone in and through but they had actually torn chunks of flesh off her arm," Mr Milne said. She had stayed in hospital overnight and was discharged on Tuesday morning, but was re-admitted that afternoon.
"She was frightened and very upset," he said. "It left her feeling very fragile."
The woman had lived in the area before and had been back visiting friends.
Animal Control staff had one of the dogs but police were still searching for the other, Mr Milne said.
"By the time I was able to speak to the owner they had taken one of the dogs to some other place," he said. "They haven't been very helpful."
Police were talking to Animal Control staff over what action would be taken.
Mr Milne said within the last six months in the same area of the town a young child and elderly man had been bitten.
"Dog ownership isn't a right, it's a privilege," he said. "Responsible dog owners ensure that their dogs cannot hurt other people or animals."