Lyon face being banned from European competition after being charged by Uefa for crowd trouble before Thursday's Europa League defeat by CSKA Moscow.
The French side currently have a ban, suspended for two years from April 2017, hanging over them after trouble at a Europa League quarter-final.
Uefa rules state: "If a further offence is committed during the probationary period, the original disciplinary measure [must] be enforced. This may be added to the disciplinary measure imposed for the new offence."
Lyon have been charged with racist behaviour, crowd disturbances, throwing objects and setting off fireworks and blocking stairways.
European football's governing body will deal with the case on 31 May.
Lyon are fourth in Ligue 1, two points behind Marseille, with the top three teams qualifying for the Champions League and the fourth placed team going into the Europa League.
Police say up to 150 ultras attacked officers outside Lyon's stadium on Thursday.
The club condemned the "intolerable and premeditated attacks" by their own fans, which they said were "detrimental".