The attack on a school in Arras, northern France, was the result of "barbaric Islamist terrorism," French President Emmanuel Macron told reporters on Friday, adding that police had helped avoid another attempted attack elsewhere in France.
Earlier on Friday, a teacher was killed in a knife attack in Arras, and the investigation was handed to the anti-terrorism prosecutor's office.
"The teacher who was killed had come forward to protect others and had without doubt saved many lives," said Macron.
The BBC reported that the attacker was a former student at the school and has been taken into police custody.
"No connection to war in Israel"
Nothing so far points to a potential link between the attack and the war in Israel, a police official told Reuters.