Seven Manchester United supporters were taken to hospital tonight after violence flared before the Champions' League clash with Roma in Italy.
British Embassy officials in Rome said five fans received stab wounds while two others, including a 16-year-old boy, needed treatment for being drunk.
None of the stab victims is understood to have serious injuries following the clash between the rival fans outside the Stadio Olympico. Most are expected to be released by the end of the night, said an embassy spokeswoman.
Earlier the Foreign Office said two British nationals were arrested but embassy staff said they could not confirm if anyone had been detained.
Italian media have reported that six British nationals were arrested by police.
The embassy spokeswoman said: 'Seven Manchester United supporters were taken to hospital after fighting broke out on the Pont Duca d'Aosta bridge which fans cross over the river to get to the stadium.
'Five are receiving treatment for stab wounds while two others, one who was a 16-year-old boy, were understood to be drunk.
'Their injuries are not thought to be serious and most of them will be discharged in the next couple of hours. One person may be kept in overnight for observation.
'The situation in the stadium is now fine and everything is running smoothly.'
She added she could not confirm if any Britons had been arrested.
The embassy had warned travelling fans beforehand not to use the Pont Duca d'Aosta bridge because it was habitually used by Roma's notorious Ultras - a following of hardcore fans.
Scenes of violence and disorder marred the two clubs' Champions League games last season, although this season's group match in Manchester in October passed off peacefully.
Eighteen United fans needed hospital treatment in April after clashes on the terraces in Rome and outside the ground.
Italian police were accused by United club officials of handing out 'indiscriminate beatings' as they charged United supporters with batons.
Violence flared again a week later at the return leg at Old Trafford when scuffles broke out outside the ground.
A volley of missiles was thrown at Roma supporters as they entered the away end turnstiles and 21 people, including 14 United fans, were arrested.
United boss Sir Alex Ferguson had hoped tonight's game would pass off peacefully but the British Embassy in Rome had warned supporters faced a 'real danger of attack' by the Ultras.
The 1,200 British supporters who made the journey were largely shepherded into the stadium two hours before kick-off, with clear segregation in place in the less than capacity crowd.
Greater Manchester Police officers travelled to Rome and before the game warned hooligans not to attend.
They liaised with their colleagues in Italy to identify any known or potential troublemakers.
lpx88
Why the Italian fans always liddat 1
Pitot
farking roma fans. its always like that when an english team goes there.