Rival gang fights are seeing more than 130 teenagers descend on a recreation ground in the suburbs to scrap.
Plain clothed officers are now monitoring Sprowston Recreation Ground after competing groups of young people have been travelling to the green space for brawls.
Extra patrols were carried out in response to groups from the area - as well as those from Mile Cross and Heartsease - clashing, Sprowston Town Council reported.
Norfolk Constabulary and the Sprowston Youth Engagement Project (SYEP) are intervening in the hopes that the inter-gang feuds will not escalate any further.
Clare Lincoln, head of the SYEP, said: "There were lots of talks of fights and that's why the police started coming down.
"We were concerned one of the groups was attracting others to come along as well. It has been very challenging."
There has historically been anti-social behaviour issues in the public space as well as in nearby Barker Lane.
A cubicle in the gents' toilet at the recreation ground remains out of action after a suspected arson attack, while the SYEP's drop-in caravan has also been targeted recently.
Miss Lincoln said as many as 131 teenagers gathered at the recreation ground on a single evening this summer.
She continued: "A lot of kids have been coming from Heartsease and Mile Cross. At one point there were as many as 40 of them from one of the suburbs.
"It's like school-age gang wars where different people are not getting on with each other."
Miss Lincoln said CCTV is going to be installed on the SYEP's caravan after a rug was set on fire beneath the base and lights were smashed up.
Reverend Canon Simon Stokes, who is chairman of the trustees at SYEP, said: "There have been days which have been very hairy - it's really challenging.
"As well as issues at the recreation ground we have had significant issues at St Mary and St Margaret's Church with petty vandalism and arson."
Revd Stokes also said yobs have recently daubed graffiti on St Cuthbert's Church in Wroxham Road having scaled scaffolding outside.
He added: "Fortunately we were able to get it cleaned off.
"The police presence has been a huge help this summer.
"Without them we would probably have had to pull workers and volunteers out for their own safety."
Sprowston Town Council chairman Bill Couzens has personally visited the recreation ground in the evenings.
He added a police presence has helped to crack down on the confrontations.
Mr Couzens said: "We started closing the rec half an hour earlier to help with the issues.
"It has been very hot during the school holidays and there have been a lot of young people about.
"We have had plain clothed officers out and and as soon as these people see police cars they will leave."
PC Graham Gill told Sprowston Town Council at its recent meeting that the ages of the gang members ranges from 13 to late teens.
He has also noticed an increase in abandoned Beryl bikes and scooters in the area.
Natasha Harpley, Labour district councillor for Sprowston, said: "There has been an increase and escalation of anti-social behaviour at the rec but the town council - along with the SYEP - are working very hard to address it.
"I appreciate this can impact the confidence of other people wishing to use the park but I hope the work being done and the engagement from the police will have this nipped in the bud fairly soon."
John Ward, Conservative county councillor for Sprowston, said: "If the council asks the police to attend to incidents they will be prompt and patrol the area."
Marcus Moore, 36, who lives near the parks, said the green spaces have resembled a "fight club" recently.
He said: "I generally feel safe but it depends what time you walk past there. It can get very busy with groups of kids around 4.30pm."
A Norfolk Police spokesperson says, “To add clarity to the report, it is groups of teenagers who have been causing concerns.
"Tackling anti-social behaviour in the area is a local priority and officers have altered shift patterns and have been carrying out both plain clothes and high visibility patrols in the area around the recreation ground.
"Different crime prevention methods have been discussed with the landowner and we are continuing to work with partners, including the Sprowston Youth Engagement Project, to engage with young people in the area.
"We would encourage anyone who witnesses anti-social behaviour to contact us on 101 or 999 if there is a crime in progress."
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