A French soccer match between Olympique de Marseille and Olympique Lyonnais was cancelled after Lyon's team bus was pelted with stones.
Footage showed damage to the windows of Lyon's bus as well as a bus carrying Lyon supporters.
Coach Fabio Grosso was also injured, and was seen being led into the stadium by two assistants while covering his face with blood-stained hands.
"Based on Lyon's wishes... the decision was taken not to start the match," said referee Francois Letexier.
He said reports of the incident "have been forwarded to the relevant authorities who will decide what action to take."
Seven suspects had been arrested on Sunday night, French Sports Minister Amelie Oudea Castera said.
Lyon coach Fabio Grosso injured
Grosso was injured by falling shards of glass and required medical treatment.
"He is better now. Twenty minutes ago it was difficult to have a conversation with him," Lyon club president John Textor told reporters.
"Once the window was broken, other projectiles hit him, just above the eye. There were beer bottles, which hit him on the forehead."
"He's a strong guy but it took him a bit of time to recover."
Lyon assistant coach Raffaele Longo was also injured.
Marseille's club president Pablo Longoria also called the incident "completely unacceptable."
"My first thought is for Fabio Grosso, someone I respect and have known for a long time," he said. "I went to see him as soon as I arrived at the stadium, I saw how he was."
