A spokeswoman at Altnagalvin Hospital in Derry last night confirmed that 12 people, all either Derry or Armagh Gaelic football supporters, were treated in the hospital's casualty department hours after Derry had beaten Armagh in their Ulster championship clash.
The trouble flared in the Brandywell area, close to the Celtic Park venue for the championship match, two hours after the match ended.
An RUC spokesman said it received reports of trouble at about 7 p.m. but no police officers were needed to quell the disturbances.
A spokeswoman for the hospital's casualty department said it treated 12 admissions for cuts, bruises and facial injuries. All 12 were later discharged most discharged themselves.