A teacher has been beheaded in a suburb north-west of the French capital Paris, with the attacker shot dead by police.
The victim is said to have shown his students cartoons of the Prophet Muhammad, an important Islamic figure.
It is considered highly blasphemous in most Islamic cultures to visually depict Muhammad.
The anti-terrorism prosecutor is to lead the investigation into the attack which occurred Friday near a school.
Education Minister Jean-Michel Blanquer tweeted that the killing was an attack on the French Republic.