One student has been killed and at least three people were injured in stabbing at a private school in western France, French media say.
The attack took place at Notre-Dame-de-Toutes-Aides school in Nantes on Thursday afternoon, according to reports.
The attacker is said to have been arrested at the scene after being restrained by a teacher.
A significant police presence and emergency services were sent to the school, which was evacuated.
Eye-witness accounts in local media described students running through the site, with some confined to classrooms after an alarm was sounded.
Ouest France reported that parents had been informed about the attack and that authorities helped students gradually leave the scene.
Rue des Épinettes, where the school is located, has been closed off.
France's Education Minister and Interior Minister are due to visit the school on Thursday afternoon.
Élisabeth Borne wrote on social media that she would "express my solidarity with the victims".
Nantes public prosecutor Antoine Leroy is said to have visited the school and will hold a press conference at 19:00.