ROME: Tens of thousands of fans poured into Rome on Wednesday ahead of an epic Champions League final between Manchester United and Barcelona in a carnival atmosphere despite a heavy police presence.

Supporters of both sides dressed up as Roman legions and gladiators, posing for pictures around the Colisseum and St Peter's Square in the countdown to the evening kick-off, some of them sharing a drink at cafés despite an alcohol ban.

"There is a great atmosphere in the city centre. It's nice to see the two sets of fans mixing so well," said one Manchester United fan who gave his name only as Dave and had travelled with a friend from London for the match.

"We spent the morning down by the Colisseum and it seemed to be four to one Barcelona fans."

Police said there had been no serious incidents of violence but some 10,000 officers have been mobilised for the operation amid fears that hardline fans of AS Roma, known as the Ultras, will try and attack English fans.

A small number of English and Spanish police were also on duty, both in uniform and undercover.

While some 50,000 fans of both teams have tickets for the match at the Stadio Olympico, many more have travelled to the Eternal City to witness the play off between two of the world's most famous football teams.

Police prefect Giuseppe Caruso said his officers were keeping an eye out for "a few dozen" hardcore English fans who could pose a potential hooligan problem.

The main fear is of violence between English and Roma supporters in a replay of the clashes that broke out when United played in the Italian capital in December 2007.

Fans from other English clubs, including Arsenal and Liverpool, have also been attacked during ties in Rome in recent years.

Police said they had only had to deal with minor incidents so far although one English supporter was slightly injured after being stabbed in the early hours.

"At about three o'clock in the morning (2:00 am), an English supporter was slightly injured in the thigh by a blow from a knife," said a police spokesman.

"We don't yet know the exact nature of this incident but it was possibly related to a fight although we cannot confirm that it had anything to do with tonight's match."

Three Spanish fans were arrested as they were driving into the capital, with clubs and a sharpened weapons confiscated from their vehicles.

Two United fans were also arrested at known trouble-spot Campo de Fiori for being drunk and bothering passers-by.

While shopkeepers have been grateful for the influx of tourists, some residents of the city have been less than pleased to have so many fans -- many of them wrapped in their team's flags -- on their doorstep.

"When I tried to go home last night, my street was blocked by dozens of English fans. They were knocking back pints of beer and chanting loudly," said one Rome resident who gave her name as Maria and is five months pregnant.

"My neighbours chucked some buckets of water at them but they wouldn't budge so I had to make a detour to get home."

Many of the players' wives and girlfriends will also be on hand at the game, and were pictured in Italian designer fashion as they flew out of Manchester and Barcelona.

Stacey Giggs, wife of veteran United winger Ryan, was among those who caught the Roman theme, dressed in a gladiator-style metal studded vest top.

The players themselves were keeping a low profile prior to kick-off but Swiss referee Massimo Busacca and his two assistants did venture out to the Vatican where they received an audience with Pope.