Rumors surrounding the attack suggest that the teacher had presented caricatures of Muhammad, which the attacker took as an incentive for the murder.
The January 2015 attacks in Paris, where no less than 17 people lost their lives, were claimed by the Islamic state.
Synagogues in Belgian capital closed on Shabbat for the first time since World War Two, Rabbi Avraham Gigi tells Israel's radio 103 FM.
Police confirm there had been shootings and explosions at the stadium, but not the number of casualties.
Though it seems this is not such a case, in recent years France has seen several cases of extreme violence against Jewish victims whose attackers singled them out because they were Jewish.
Mireille Knoll, 85, was found dead on Friday at her apartment in Paris's central 11th district. She had been stabbed multiple times and her flat set alight.
How the suspect, from a broadly secular background with a history of petty crime, was transformed into an alleged cog within extensive Islamic State cells operating in Belgium and France is unclear.
The incident was one of several cases in France in recent years in which criminals apparently singled out Jews based on the belief that they have money.
The November 2015 Paris attacks marked as the day defense establishment changed its perspective.