Italy soccer attack stokes fears of rising right-wing violence ROME (Reuters) - A brutal attack on fans of English football club Tottenham Hotspur in Rome has stoked fears in Italy of rising right-wing and racist violence. Italy's capital has been rattled by increasing militancy by the extreme right since October, often with racist overtones. Weekly demonstrations by the neo-fascist youth group Blocco Studentesco have often ended in clashes with police. Local media initially blamed Thursday's attack on hard core fans or Ultras supporting Lazio, the team Tottenham had traveled to the capital to play in the Europa League. But two fans of AS Roma, Lazio's bitter city rivals, were among the 15 detained for alleged involvement in the mass attack on a downtown bar, suggesting a possibly different motivation. Witnesses told local media masked men armed with knives and baseball bats shouted "Jews, Jews" as they laid siege to a pub where the Tottenham fans were drinking in a district popular with tourists in an old quarter of Rome. Ten people were injured in the attack and 25-year old Ashley Mills was left in a critical condition. He was still in hospital on Friday, and the Italian news agency Agi said he was undergoing surgery after suffering internal bleeding. Israeli ambassador to Italy Naor Gilon told reporters the attack on the Spurs fans, many of whom are Jewish, stemmed from "a new trend of anti-Semitism in Europe." Rome mayor Gianni Alemanno expressed deep concern about the attack and hoped the police would quickly track down those responsible. "What happened shows that there is a group of madmen and thugs running around and hiding behind the fans in our stadiums, and this is unacceptable," he told reporters. The European far right has gained increased support as the continent's economic crisis has deepened, especially in the debt-laden south. Its most startling rise has been in the worst hit country, Greece, where the anti-immigrant Golden Dawn group has flourished. Italy is no stranger to the trend. Last week police arrested four people for allegedly inciting racial hatred through the website of the white supremacist movement Stormfront, confiscating a variety of weapons and neo-Nazi propaganda, after the group published a list of prominent Jewish citizens. Teenagers carrying neo-fascist flags stormed a high school last month, tossing smoke bombs into classrooms as lessons were being taught, in a raid interpreted in Italy as an attempt by Blocco Studentesco to assert control over its turf. Shortly afterwards a school due to host a meeting with local authorities about the "neo-fascist resurgence in schools" was daubed with swastikas, Celtic crosses and the word 'Hitler'. There is no suggestion the Blocco is linked to the attack on the Tottenham supporters. "We are proud to be fascists," the 18-year old Rome leader of the Blocco recently told Reuters in a suburban cafe, where swastikas had been scrawled across walls and furniture. Israeli flags are a common sight among Tottenham supporters at matches, and fans refer to themselves in chants as the 'yid army'. Lazio have long had fans with extreme right-wing sympathies, notorious for making Nazi salutes, unfurling anti-Semitic banners and chanting racist insults against black players. At the game on Thursday, which ended in a goalless draw, Lazio supporters unfurled a banner reading 'Free Palestine'. The English Football Association plans to send a report to European soccer's governing body UEFA following alleged anti-semitic chanting by Lazio fans during the match on Thursday. Spurs manager Andre Villas-Boas has demanded an investigation. Lazio was fined 40,000 euros ($51,500) for racist chanting against black players in another match against Tottenham in London in September. ($1 = 0.7761 euros) Reporting by Naomi O'Leary; editing by Barry Moody/Mark Meadows