France is set to deploy and mobilize 7,000 soldiers across the country following the fatal stabbing of a teacher in a school by a former student suspected of Islamic radicalization.

The school reopened Saturday morning, days after the attack that shocked the nation.

Counterterrorism authorities are investigating the incident as the suspected assailant and several others remain in custody, prosecutors said.

Intelligence services for radicalization had been surveying the suspect before the attack took place.

Court documents viewed by The Associated Press show the suspect is from the Ingushetia region in Russia’s Caucasus Mountains, which neighbors Chechnya