A group of Italian 'Ultras' carried stones and rocks to attack Tottenham Hotspur supporters in a bar in Rome, according to the pub landlord.
The Premier League outfit have confirmed that nine of their fans were injured following a brawl, which is believed to have left an individual seriously injured after getting stabbed, in the city centre.
Landlord of the Drunken Ship pub Marco Manzi told the Irish Independent: "The bar was full of about 30 English supporters at 1am. Most of them were aged between 40 and 50 and they were well behaved.
"Then arrived what I presume were Italian supporters wearing scooter helmets with their faces covered with scarves carrying stones and rocks.
"They arrived in the pub and they attacked the English supporters. Some of the English supporters tried to escape down Via dei Cappellari and it was in this street where one of them was hit by a knife. I think he was quite badly hurt but I don't know any more about him. The whole operation from start to finish was over in around 10 minutes. Most of the fans left and the police arrived."
The incident occurred ahead of tonight's Europa League match against Lazio.