At around 6.20pm on Wednesday, June 23, officers were called to reports of an incident in the Kingsway Recreation Ground.
A gang of young men were reported to be fighting in front of the children’s play area.
PC Jordan Lancaster said: “This incident took place where families with children were using the recreational facilities.
“The actions of those involved caused others to fear for their own safety, and we will not tolerate this behaviour.
“We are keen to speak to anyone with information, however small, about this incident.”
Two 18-year-old men and a 17-year-old boy from Luton have been arrested and released on bail.
Anyone with information is asked to report it online or call 101, quoting reference 40/32281/21.
Alternatively, contact Crimestoppers anonymously, on 0800 555 111.