It is the second time this season Saint-Etienne have been hit with a stadium closure by French football authorities. They hosted Clermont in November in front of empty stands after protests from angry fans delayed a game against Angers.
Saturday’s 4-1 defeat by Monaco was interrupted twice, with the second delay lasting 30 minutes as supporters set off flares and fireworks at the Stade Geoffroy-Guichard.
The incidents will be reviewed in full by the French league’s disciplinary committee, which will make a final ruling on May 18 — three days before the final match of the season.
Saint-Etienne, 10-time French champions, play three of their last four games away from home. They are due to host Reims on May 14.
Pascal Dupraz’s side are two points from safety in 18th place.
French football has been rocked by repeated incidents of crowd violence this season. Lyon and Paris FC were thrown out of the French Cup after fans clashed in their tie in December.
Lyon and Nice were also docked a point in the league as games against Marseille were abandoned after Dimitri Payet was struck by a bottle thrown from the terraces on both occasions.