Hamilton police are happy a large scale alcohol fuelled disorderinvolving 40 police and around 200 teenagers was contained last night.

While the disorder in the city was difficult to deal with, police say the fact it was contained is testament to the value of a recent realignment in the district.

Inspector Karen Henrikson says around 40 police were required to quell the disorder that broke out on Hammond Street near the Hamilton Lake about 11.30pm yesterday.

"Police first became aware there may be an issue about 5pm thanks to members of the public who advised there was a party planned at the address and several hundred people had accepted invitations to attend on Facebook.

"Recently we introduced a District Command Centre to keep an eye on of developing situations from a prevention perspective. Because of the notification this centre liaised with the Northern Communications Centre and a patrol was sent to check the address at 7.30pm but no-one was home."

While all was quiet Karen says that wasn't the case a few hours later when local residents rang 111 about 10pm to advise a large group of young teenagers were partying in the street.

"Police attended however there were no reports of any fighting, more a loud party and the organisers were spoken to. Approximately an hour later though it was a different story with even larger numbers of drunken youths out on the street fighting and police arrived in numbers.

"Our Tactical Response Unit approached the scene but was pelted with bottles and other missiles requiring them to retreat call in for reinforcements and don protective public order equipment."

Karen says skirmish lines were formed to clear the streets and four arrests were made.

"Unfortunately some of the dispersed youths turned their anger on an ambulance near the entrance to the lake and it came under attack from flying bottles necessitating the crew, who were on station to treat any injured members of the public, retreat to a safer location.

"Though the number of youths involved was quite large, police were able to control not just them but also successfully manage the Ballons Over Waikato and maintain a presence in the city's bar zone thanks to the additional staff provided at peak times as part our current rostering model."

Karen says this deployment model is known as the Peak Load Roster and means that at particularly busy times sufficient staff are available to call on.

"It's all about having the right people at the right place at the right time to prevent incidents like this from getting out of control.

"One of the things that is quite clear to police is the risks associated with publicising parties on social media and the need for organisers to be aware of who is coming to their events

"Another issue is people making alcohol available to underage partygoers. Our enquiries into what occurred last night are continuing and we have not ruled out taking further action."