Police are investigating a fight at the Christchurch youth justice facility Te Puna Wai ō Tuhinapo on Monday night which saw five staff and three youths injured.
The new Minister for Children says she won't tolerate it and is considering a rewards system that doubles as a punishment.
"My understanding is that they were of the older age group, 17 and up," Karen Chhour said.
She said the fight was started by five young people in the Muriwai unit at the facility.
"We have five staff members and three youth that have ended up seriously injured and that is not OK and I want to make it very clear from day one that it will not be tolerated."
Police are investigating the fight, which is the latest in a string of security incidents exposed at youth justice facilities around Aotearoa.
There have been escapes, MMA fights instigated by staff, and in July there was a 24-hour standoff with teens on a roof. Fried chicken was used to entice them down and Chhour said the KFC gravy train is over for misbehaving youths.
"I'm working with different ministries at the moment to seek advice from multiple ministries like justice as well about what we have to do to make sure there is actually serious consequences for this kind of behaviour," the minister said.
Labour's Chris Hipkins said: "Let's see in the fullness of time how they handle these issues."
But the youths detained in facilities are already enduring some of the harshest punishments available, so the minister is considering a rewards system.
"There are ways that we can incentivise young people if their behaviour is going well within a facility, we may be able to seek advice on how we can actually end where there is reward for good behaviour."
She said she was seeking advice on what those rewards could be.
The aforementioned serious consequences for bad behaviour could then be no rewards.
"Those that are misbehaving and not complying to how they should be will not receive those rewards and make sure that bad behaviour is not rewarded within these facilities," Chhour said.
The new minister setting expectations of punishment, but without concrete details on what punishment she wants.
