The attack on Liverpool supporters in Naples on Tuesday night was 'unmotivated', according to a chief police officer.
The Reds take on Napoli in the Champions League on Wednesday evening, with the away fans told to be wary about their safety in Italy ahead of the encounter.
There have been a number of high-profile incidents involving Italian fans in recent years, including Liverpool supporters being stabbed in 1984 and 2001 by football hooligans in Rome.
Now, there has been another reported attack, which has left a senior officer in Naples disappointed because it doesn't reflect well on the city.
"The incident last night was completely unprompted and unmotivated,” Chief of Police, Antonio De Iesu said on Radio Crc, as quoted by Football-Italia.
"These events don’t reflect well on the city, we’ve made appeals to the fans but obviously, they don’t get through to the younger groups.
"These are actions which have nothing to do with football. The men of DIGOS [special operations] have been carefully observing the city, and in fact, have identified 28 men of various fan groups."
Prior to a ball being kicked, both clubs were hoping that events on the pitch would do the talking, but now the reported incident will steal the headlines. Jurgen Klopp's men will be looking to maintain their winning start in Group C following their late winner against PSG on the opening night of the competition.