UEFA will investigate separate incidents involving fans of both Marseille and Manchester United after their actions during the game between the two clubs at the Stade Velodrome on Wednesday.
Reportedly, seven United fans were taken under arrest on the day, with four of them held responsible for lighting a flare in the away section of the ground. In December, Chelsea fans who were found guilty of the same offence during their group stage tie at the Stade Velodrome were handed six-month prison sentences.
Marseille supporters will also be investigated by the UEFA after evident attempts to distract United players with the use of laser pens. After the game, television cameras also caught lasers being aimed at Patrice Evra, a key member of France's World Cup mutiny, who was booed all night for his role in the World Cup debacle. Three years ago, Lyon were fined €3,200 for incidents of an unsporting nature for using laser on then Manchester United player Cristiano Ronaldo.
UEFA will hold a disciplinary panel hearing on the cases on March 17.