The dog then jumped over a pallet and chased the teens, latching on to one, with some suggestion the dog owner had set his animal on to the group.
The attack happened the same day as animal behavioural expert Prof Kevin Stafford, of Massey University, called for owners of dogs that attack to be charged with assault and even manslaughter if the result is deadly.
"It is nonsensical that a dog can kill a person in New Zealand and the owner may be charged under the Dog Control Act for not having control of the dog," he said.
Fairfax also reported that a 10-year-old boy was taken to hospital after he was wounded by a dog in Waihi on Wednesday.
On Tuesday night, a heavily pregnant woman was attacked by a dog in Christchurch.
Animal management officers there have not been able to speak to the victim at this stage. She is still in hospital and has asked for some space before making a statement.
Officers will get statements from witnesses and the dog owner over the next couple of days, it was confirmed today.
And on Saturday, Darnell Minarapa-Brown, 7, was attacked by his uncle's dog in Auckland, leaving him needing more than 100 facial stitches. The dog was euthanised.