It happened at Newry Showgrounds in the city’s Greenbank Industrial estate area last night just before 10 pm.
Sergeant Michael Gallagher said: “We are currently investigating an incident which occurred following a football match between Newry City AFC and Portadown Football club.
“We received a report that a number of vehicles had been damaged in the Showgrounds’ car park and that one man had been injured with a bottle. Another man was reported to have been injured in a fall from the roof of a car.
“The NI Ambulance Service also attended and treated one person at the scene. Another was taken to hospital for treatment to injuries that are not thought to be life-threatening at this time.
“Police will be working alongside both football clubs with the aim of identifying those involved.
“If you believe you can assist us with our enquiries, please contact 101 and quote reference number 1679 of 20/4/18.
“Alternatively, information can also be provided to the independent charity Crimestoppers on 0800 555 111 which is 100% anonymous and gives people the power to speak up and stop crime.”