Police in Amsterdam say they fired a water cannon at football fans "to put out flares and prevent unsafe situations" ahead of the first leg of the Champions League quarterfinal between Ajax and Juventus.

Local broadcaster AT5 showed images of scores of chanting fans being hosed by the water cannon and responding by tossing fireworks and flares at police before mounted officers charge at them followed by riot police.

There was no immediate word on arrests.

Earlier Wednesday, police in the Dutch capital said they had detained dozens of Italians suspected of possessing flares, a knife, pepper spray and fireworks.