Visiting supporters from English Premier League club Tottenham were injured after suspected hardline fans of Lazio attacked a pub in the Italian capital, Rome, reports said.
Lazio host Tottenham at the Olympic Stadium later Thursday for a Europa League match to which English icon Paul Gascoigne, a former star of both clubs, has been invited to attend.
However any festivities are set to be overshadowed by the latest incident to marr Rome's reputation as one of the most dangerous cities for visiting fans from England.
One of those injured had to attend hospital after the attack, which occurred in the early hours of Thursday morning when a group of Italians wearing masks attacked the premises, according to witnesses quoted by the ANSA news agency.
The Gazzetta dello Sport newspaper said the injured supporter had suffered a stab wound. He had been among a group of 10 fans which included nine English and one US national.
Gazzetta quoted the owner of the Drunken Ship pub, Marco Manzi, as saying: "Everything looked planned, they were extremely organised. They blocked the second exit and were even armed with tear gas.
"They managed to isolate the English and started hitting them with bars, chairs and tables."
The report added that seven of those attacked were taken to hospitals across the city, but that only one - who had been stabbed - was kept in due to the seriousness of his injuries.
Lazio president Claudio Lotito condemned the attacks but said he would make no further comment until the facts had been established.
"These kinds of acts must always be condemned but from the information we currently have it is not clear this assault is the work of Lazio fans," the report quoted him as saying.
The incident is one of many involving hardline fans of Italian clubs and fans from England.
A number of Liverpool supporters were stabbed after a European Cup final triumph against AS Roma in 1984.
Since then fans from Liverpool, Middlesbrough and Manchester United have all suffered violence in Rome over the years at the hands of ultras from the city's two Serie A clubs - AS Roma and Lazio.
Gazzetta added that after the most recent attack the assailants fled through the streets of Rome disposing of iron bars, knives and other weapons.
One reportedly jumped on a bus and was seen boasting of the assault, upon which he was photographed by the startled bus driver.
Police have reportedly caught and detained six of the estimated 40 assailants, who are believed to be between the ages of 20 and 45.