More than 100 young people were involved in an illegal rave that spiralled into a brawl, it has been claimed.
The outdoor party at the Falls Park in west Belfast was one of a number across the city.
The PSNI said it was working in partnership with Belfast City Council to put on more patrols in the area to try and reduce incidents.
Youths started to gather at the park around 6pm on Monday and were drinking until the early hours of yesterday morning.
Residents reported bottles being thrown at passing cars and there was a report of windows in a private hire bus being smashed.
At around 10pm it is understood that fights began erupting among the young crowd gathered in the park.
One resident described the scene as a "mass brawl with hundreds of teenagers in the park".
They complained that both gates in the park had been left open, as well as the gates to nearby Milltown Cemetery.
Householders also claimed that staff at a nearby garage were having to shield some teenagers who were hurt.
There were also complaints of anti-social behaviour at River Walkway in the Lower Ormeau area of south Belfast.
SDLP councillor Tim Attwood said trouble in the Falls Park has been a regular occurrence in recent years.
"It is an ongoing issued both in Falls Park and the City Cemetery," he said.
A spokesman for the PSNI said it was patrolling the area in an attempt to reduce the number of anti-social incidents.
"PSNI are aware of ongoing incidents and are working in partnership with Belfast City Council including joint patrols and we will continue this approach in an attempt to reduce incidents in the area," he said.
A Belfast City Council report last year found that the number of incidents of anti-social behaviour at parks across the city had shot up to 441 between December 2013 and April 2014.
There were 281 in the same period the previous year.
The worst area of the city was Upper Falls where 142 incidents were recorded in that period - five times as many as the previous year when just 28 were recorded.
The next worst was the Pottinger area in east Belfast where the incidents leaped from 40 to 104.
In the Laganbank area of south Belfast the number of reported incidents rose from 16 to 77, while in the Victoria area of east Belfast numbers increased from just six to 34.