Vandals smashed the windows of cars parked outside a football stadium in north Belfast on Monday.
At least three vehicles were targeted in the attack at Seaview, which happened around 15 minutes into the semi-final of the Steel & Sons Cup match between Belfast Celtic and Newington FC.
Since there are no dedicated car-parking facilities at Seaview, players, spectators and staff park on the Shore Road and in the surrounding residential areas.
A home-owner is believed to have notified officials what was happening after they heard a car alarm going off.
An announcement was then read out in the stadium, giving the registration numbers of the damaged cars.
It subsequently emerged that one of the targeted vehicles belonged to Belfast Celtic player Ciaran Donnelly.
Belfast Celtic chairman James Gillen condemned those responsible for the attack and said the players and members of staff were very disappointed. Mr Gillen added: "It was such a great occasion. The game went off well and was played in the right spirit with a big crowd.
"When you get things like this, it is just very disappointing.
"We have had no trouble with anyone before. Everywhere we have been, we have made friends. That's what made it so disappointing".
Mr Gillen suggested the vandalism was more than just anti-social behaviour and may have had a sectarian motive.
"It's Newington from the Antrim Road playing Belfast Celtic from west Belfast on the Shore Road," he said.
"It is very clear what has happened - some people are just not prepared to move on. I know you call the club Belfast Celtic, but in the team there are people from both sides of the community".
The PSNI said: "At around 8.25pm, it was reported that three cars parked in the area had their offside driver's window smashed.
"Two males aged between 17 and 18 years old and wearing dark clothing who were believed to have been involved made off towards the Northwood Crescent area following the incident.
"We would appeal to anyone with any information or who saw anything suspicious in the area to contact police on 101, quoting reference number 1910 of 25/11/19".