Anti-Semitism is believed to be behind the attack on a group of Tottenham Hotspur fans by Italian hooligans in Rome, which left one supporter in a critical condition.

Eyewitnesses told Italian newspaper La Gazzetta Dello Sport that the group of about 40 assailants, who stabbed two Tottenham supporters and injured a further eight, were yelling "Jews, Jews!" as they assaulted the Drunken Ship pub in central Rome.

Spurs have a large Jewish fanbase, and the term 'Yids' is regularly as a term of abuse by rival supporters.

Pub owner Marco Manzi told the Gazzetta that the hooligans "were all dressed the same with a helmet covering the head and no other distinguishing sign.

"It was planned. They were very well organised: they blocked the back door and also had 'stinging gas'. They cut the Spurs fans off [from other guests] by throwing stones, wrenches, tables and railings, then they assaulted them."

Italian police, who reportedly took more than 20 minutes to arrive on the scene, have so far arrested six people. The oldest is 55 years old, the youngest 20.

Another 15 people linked both to football and anti-Semitic violence are reportedly under investigation.

The incident happened ahead of Tottenham's Europa League match against Lazio, a club renowned for a hardcore following which has a history of far-right and racist behaviour.

However Lazio president Caludio Lotito has denied the attack was perpetrated by his team's supporters.

A tattoo on the arm of a Lazio fan. (Twitter) Twitter