Two men were arrested for possessing weapons after reports of "a number of incidents" on Northampton's Racecourse on Saturday evening.
Northamptonshire Police said they had not received any reports of people being stabbed or acid being thrown during the incident.
Officers were called to a large number of people involved in a fight on the park at about 6.30pm on Saturday, June 9.
The reports suggested a number of the people involved in the disorder were carrying knives.
A 16-year-old boy and an 18-year-old man, both from the Coventry area, were arrested and have both been released under investigation pending further inquiries.
Two knives were recovered by police.
Chief Inspector Lara Alexander-Lloyd said: “I would like to take this opportunity to reassure people that we are investigating the disorder that took place at the Racecourse on Saturday evening.
“Officers quickly attended the scene and made two arrests. A large police presence remained on the Racecourse for the remainder of the night in order to respond to any further incidents and provide reassurance to members of the public.
“We have not received any reports of people being stabbed or acid being thrown during the incident. I can also confirm that at no point did police officers discharge a Taser while making an arrest.
“There was no intelligence or information to suggest the disorder was going to happen and we are working closely with the force where the people who were arrested are from.”
As a result of the disorder, officers were granted additional stop search powers for the Racecourse and surrounding roads from 7pm on Saturday to 10am on Sunday, June 10. These additional powers were granted under Section 60 of the Criminal Justice and Public Order Act 1994.
This is a distinct power that allows officers to conduct searches without ‘reasonable suspicion' but only when a chief officer believes strict criteria have been met and it is needed to prevent serious violence.
During the time the power was in place four people were stop searched by officers.
Chief Inspector Alexander-Lloyd said: “I would like to take this opportunity to thank those people who attended the carnival for their co-operation and support on Saturday evening.
“Members of the Northampton neighbourhood team were in attendance at the event, engaging with the public and were able to quickly respond to the disorder.
“It is disappointing that a number of people travelled to the town and caused the trouble we saw when the carnival itself had been such a success celebrating the many communities we have in Northampton.”