West Ham fans clashed with riot police in Prague as they celebrated their Europa Conference League triumph on Wednesday night.
A scuffle broke out in the Czech capital after police officers tried to confiscate a flare as supporters gathered in the Old Town area of the city.
Riot police stormed a group after they lit a second flare, with fans responding by throwing bottles and missiles at officers.
As many as 20,000 West Ham fans were in Prague to see their side beat Fiorentina 2-1 and thousands had travelled without a ticket.
Before the match, Czech police said they had detained at least 16 Italian fans after they attacked West Ham supporters outside a bar. Czech police said three people were injured in the incident, with one police officer being attacked.
West Ham have condemned the behaviour of fans who left Fiorentina captain Cristiano Biraghi bloodied after pelting him with missiles during the match.
Supporters threw a dozen plastic pint cups and a vape at Biraghi, who suffered a gash to his head. West Ham now face action from Uefa.
BT Sport pundit Joe Cole said: “It’s moronic behaviour. I’ve had it myself being hit by things - it needs to be sorted out and taken out of the game.”
West Ham said in a statement: “West Ham United unreservedly condemn the behaviour of a small number of individuals who threw objects onto the pitch during tonight’s UEFA Europa Conference League final.
“These actions have no place in football, and do not in any way represent the values of our football club and the overwhelming majority of our supporters, who have behaved impeccably in Prague this week and throughout our last two seasons in European competition.
“We will work with the Police and other stakeholders to review the incidents and act against anyone found guilty of an offence.
“In line with our zero-tolerance approach, anyone identified will have their details passed to the police and will be given an indefinite ban and therefore be unable to enter London Stadium and travel with the club.
“There is no place for this kind of behaviour at West Ham United.”
