French prosecutors are reportedly holding nine people in custody in connection with the killing of a school teacher outside Paris. The junior high teacher had shown his students a caricature of the Prophet Muhammad as part of a class on freedom of expression.
Local media say the teacher likely angered some Muslim parents of students as news of the caricature spread online.
Police found the teacher's body with a knife wound to his neck when they arrived at the scene after receiving a telephone call about a suspicious man on Friday.
The officers shot the man dead after he reportedly yelled "God is great" in Arabic and attacked them with a knife.
Media reports say that the 18-year-old suspect was from Russia and was of Chechen origin.
The nine in custody include family members of the suspect and parents of the school's students.
In 2015, Islamic extremists stormed the office of satirical magazine Charlie Hebdo in Paris, killing 12 people, after the magazine published a caricature depicting the Prophet Muhammad.
Last month, a man from Pakistan stabbed two people outside the former offices of Charlie Hebdo after the magazine republished the caricature.
While many people in France strongly support the idea that criticism of a religion should be allowed as part of freedom of speech, Muslims as well as people in many Middle Eastern countries strongly oppose it and see it an insult to their religion.
French President Emmanuel Macron visited the site of the attack and said a compatriot had been murdered because he was teaching about freedom of expression.
Macron said the teacher was a victim of a terror attack by an Islamic extremist and called on French people to stand united against terrorism.