Nantes, a 15-year-old student fatally stabbed a classmate and injured three others at a high school in the city of Nantes before teachers were able to subdue him, police said.
BFM TV reported that the victim was a girl and the three injured were boys. The police have not confirmed the ages or genders of the victims.
The teaching staff successfully restrained the attacker at the private Catholic school Notre-Dame-des-Toutes-Aides before law enforcement agencies arrived, a police spokesperson said.
They clarified that no elements indicate a terrorist motive.
Students were kept inside the school after the attack, but they were able to leave the premises under police protection in the afternoon. Dozens of parents were waiting outside.
"We are waiting to take them in our arms... so we can help them recover from the stress that may arise from this," said Nicolas, a parent of one of the students.
The police did not disclose the identity of the suspect and provided no explanation for the reasons behind the attack.
Local newspaper Ouest-France reported that the attacker was dressed in black and wearing a helmet and mask. According to the report, two knives were found near his belongings.
BFM and other media reported that the suspect sent a document to all students at the school via his email account, in which he described a dark vision of society, without mentioning any potential attack.
Media outlet Franceinfo clarified that the knife attack occurred after a conflict among students.
The police did not immediately confirm this information.