A group of partying West Ham fans were violently set upon by Fiorentina ultras this afternoon.
The celebratory mood soured in central Prague soon after 3pm when Hammers fans drinking in a bar were attacked by a group of Italians clad in black clothing and masks.
As word went round the wider area that their fellow fans were being assaulted Hammers fans moved towards the bar - and a group of riot police moved in to prevent the two groups meeting.
It was unclear if anyone was injured in the disorder.
One West Ham fan who witnessed the scenes said: 'They targeted a group and attacked them quite violently then ran off before anyone could react.