Marseille’s Ligue 1 home match with Lyon was postponed after visiting boss Fabio Grosso was injured when his team’s bus was attacked on the way to the ground.
Images on social media showed a bloodied Grosso laid on a stretcher.
The Lyon bus was hit by rocks on its way to Stade Velodrome and supporter coaches also came under attack.
The game between bottom-of-the-table Lyon and 10th-placed Marseille was due to kick off at 19:45 GMT on Sunday.
“[Grosso] can’t hold a conversation, he had shards of glass in his face,” Lyon club president John Textor told Prime Video.
“I’m very angry – our players, our coach, prepared for tonight and the fans wanted to see the game played.”
Marseille president Pablo Longoria said the situation was “completely unacceptable”, adding: “My first thought is for Fabio Grosso, someone I respect and have known for a long time.
“I went to see him as soon as I arrived at the stadium, I saw how he was.”
Marseille issued a statement saying the club “deplores the unacceptable incidents which took place this evening around the Stade Velodrome, against the professional team bus as well as Olympique Lyonnais supporter buses”.
“The club wishes a speedy recovery to Lyon coach Fabio Grosso and strongly condemns this violent behaviour which has no place in the world of football and in society,” the statement added.
“Due to a handful of mindless people, the game planned for this evening was spoiled and deprived 65,000 supporters of attending a football match.”
Following the attack a crisis meeting was called where it was decided the game should not go ahead. French football’s governing body said its Competitions Commission would decide the next steps.
Marseille said it would comply with any decision made on the fixture’s future but hoped it “takes place as quickly as possible and under the best possible conditions at the Stade Velodrome”.
‘Terrible image for French football’
Thousands of fans were already inside the ground when the announcement was made that the game had been postponed.
“We took into account Lyon’s desires for the match not to take place,” said match referee Francois Letexier at a news conference.
“Based on Lyon’s wishes and the protocol, the decision was taken not to start the match,” he added, saying reports “have been forwarded to the relevant authorities who will decide what action to take”.
AFP reported a Lyon club source as saying Grosso, the former Italy defender, was experiencing dizzy spells.
French sports minister Amelie Oudea-Castera told the news agency: “These images are revolting. Seeing the stoned bus like that, the bloody face of Fabio Grosso… These are unacceptable acts which go against the very values of football and sport.
“I hope that the investigation will be carried out quickly, that the perpetrators are found and they are severely punished.”
French football expert Julien Laurens, writing on X, described it as a “terrible image for French football”.
“What a scandalous mess,” he added. “This is not the first time this has happened (and not the last sadly) but I have no words for this. Unacceptable again.”
Seven-time champions Lyon last won Ligue 1 in 2007-08. Grosso, 45, was appointed as their managed in September after former France centre-back Laurent Blanc was sacked.