The PSNI is appealing for information about pre-arranged fights at local football matches.
Police are aware of online communication between rival groups of local football supporters challenging each other to pre-arranged fights.
Police Service of Northern Ireland Football Co-ordinator, Inspector Gary McCullough said: “The overwhelming majority of fans that attend matches do so to support their club and to have an enjoyable day out with friends and family. They do not want disruption, disorder or criminal behaviour of any kind inside or outside the grounds.
"At football matches, or indeed any event which draws significant numbers of people, police work closely with stewards and event organisers to ensure the delivery of a safe event. It is critical that anyone who chooses to engage in violent confrontations with other fans should understand that their behaviour is unacceptable and if detected by police, will face consequences that can be far reaching and can seriously impact on their future opportunities for work and travel.
"To parents and guardians, please help prevent young people from becoming involved in these activities. Know where your children are, who they are with, what they are doing and what they are arranging on their social media accounts."