The French football club Paris Saint-Germain are facing the problem of its fans fighting with each other as social tensions in the city hit the Parc des Princes.
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Hooliganism in French football has risen dramatically over the last year, and much of it has been blamed on PSG, where fans who traditionally gather at different ends of the ground - the far-right white nationalists in the Boulogne end and the multi-ethnic fans opposite them - are continually clashing.
PSG chairman Pierre Blayau told BBC World Service's World Football programme that, while the club is doing all it can, it is reaching the limit of its powers.
"We could do still more in the way of education, we could launch still more anti-discrimination campaigns, to explain why football should remain entertainment, driven by values of mutual respect," he said.
"But there comes a point where the individuals who behave badly and cross the line - and I mean individuals, they're not supporters - become delinquents, both in our eyes and those of the authorities.
"In that case, the club doesn't have the powers of the police or the judiciary."
The clashes between PSG fans reflects the recent racial disturbances in the country.
Two weeks ago, a motorway service station near Nantes was destroyed as two PSG groups clashed using baseball bats. Last season, Auxerre police had the bizarre sight of Paris fans fighting each other within their own enclosure. Similar clashes since then in Toulouse, Lens and Paris.
"Most of the people are just here to support the team - I don't think the violence comes from supporters, just stupid guys from both sides, here to fight," explained one PSG fan.
Paris was hit with riots in October 2005
"They should just go and fight on a field, not at the Parc des Princes."
While the far-right nationalists have long been a fixture at the ground, recent years have seen another group has emerge at the opposite end - the Tigris, which is more racially diverse.
"They are Arabic, French, black, Asian - but the Boulogne are white skinhead racists, and the others don't like that," explained supporters club leader Larasse Haracet.
"This is the reason for the war between the supporters."
Patrick Mignon, a researcher and sociologist at the French National Institute for Sport and Physical Education, explained that as a result, there is political dimension to the clashes between the PSG fans, mirroring the problems in the city's suburbs.
"For some years, Paris Saint-Germain only reflected an aspect of the suburbs - the poor, white, lower-middle-class or working class suburbs," he said.
"But now, it's all the suburbs. At the Parc des Prances, you have the young, white nationalists, poor suburban kids, and the others - which are much more culturally mixed, from all kinds of racial and social backgrounds."
Sarkozy has promised new laws to tackle the problems
Now there is an increasing call for action to tackle the problem. While PSG has run several anti-racism campaigns, and has worked hard to improve its image, the conflict between rival groups has given it a new headache.
Meanwhile the French interior minister, Nicholas Sarkozy, has promised a new bill which, if it becomes law, will mean violent supporters groups could be banned.
This is of particular significance in France, where fans associations often enjoy semi-official status within the clubs.
But increasingly, France is drawing inspiration from England on how to deal with the problems. There is talk of installing monitoring cameras and issuing individual banning orders.
"There is a great atmosphere in England," said one fan.
"If we could have that here, it will be better."