Lyon have denounced groups of their supporters following an escalation in violence between OL fans and followers of their arch-rivals Saint-Etienne.
A Lyon fan, who has since made an official complaint to the police, was attacked last Thursday while a Saint-Etienne supporter was the victim of an assault on Saturday as the opposing sides of the Rhone derby continue a conflict that threatens to boil over.
Though OL only emerged as serious rivals to Saint-Etienne, the dominant French team of the 1970s and early '80s, at the turn of the century, the animosity on both sides is vehement.
The ill feeling has been increased, however, by the theft last April of part of a banner belonging to a major Saint-Etienne supporters' group, the Magic Fans, by OL counterparts who reportedly wore their hated neighbours' shirts during a Coupe de France tie with Lorient to carry out their plan. The stolen banner was then displayed during the derby between the pair later in the month, provoking violent disturbances during the game.
With both sets of supporters highly-strung, OL have appealed for calm.
"Olympique Lyonnais denounces this behaviour and is determined to make everyone aware that they can intervene at their level and so make it stop," read a press release on the seven-time Ligue 1 champions' website.
"More than the previous incidents, the attack which a Lyon fan was the victim of last Thursday and that which a Saint-Etienne supporter suffered on Saturday are inadmissable and unacceptable.
"Olympique Lyonnais would like to remind everyone that the supporters concerned do not belong to official groups recognised by the club, but are -- on the contrary -- sympathetic to groups that the club has refused to recognise because they do not correspond to the values of OL, whose conviction to fight against all forms of violence has been reinforced once again."