Clashes at the Champions League game between AS Roma and CSKA Moscow that left two fans in hospital with knife wounds will be investigated, a top European football official said Thursday.

"An investigation, if it has not yet been opened, will be opened because these are scenes that we cannot tolerate in the Champions League," UEFA general secretary Gianni Infantino told journalists at the body's headquarters in Nyon, Switzerland.

Two CSKA fans had to be rushed to hospital, one with suspected stab wounds, after victory celebrations for Roma -- who won the game 5-1 -- turned ugly, according to media reports.

"These are scenes... we don't want to see in European stadia so there will be a disciplinary proceedings certainly," Infantino emphasised.

"There will be some sanctions but it has to be established which ones," he added.

The game on Wednesday saw Roma's return to Champions League action after a three-year absence.

According to a report by Italian sports daily Gazzetta dello Sport, a Russian fan was stabbed in the stomach and the arm, while another fan was taken to hospital with head wounds after being hit with what was thought to be a bottle.

The Italian capital has witnessed several violent incidents over the years.

Earlier this year a Napoli supporter, Ciro Esposito died in after being shot by hardline ultra fans of Roma.