A 16-year-old French high school student claiming to be “possessed” and hearing voices stabbed his Spanish-language teacher to death in class Wednesday, officials said.

The deadly attack took place at a private Catholic school named after Saint Thomas Aquinas in Saint-Jean-de-Luz, a high-end beach resort town in southwestern France.

The victim was a 54-year-old female teacher who was identified by French news outlets as Agnes Lassalle.

Bayonne prosecutor Jerome Bourrier said the teenage suspect was taken into custody and interviewed by investigators Wednesday.

A criminal probe has been launched for suspected premeditated murder.

Bourrier added that the 16-year-old student had no prior interactions with police or the justice system.

A top government official, speaking on condition of anonymity, said early details communicated by the police suggest the teen suffers from serious mental health issues.

After the stabbing, the boy, who has not been publicly identified, allegedly told another teacher he was possessed and heard voices telling him to kill his teacher.

Two students who witnessed the stabbing said the suspect stood up and walked to the door, before whipping around and plunging a large knife into the teacher’s chest, local newspaper Sud Ouest reported.

Other witnesses speaking to the press said the juvenile attacker appeared calm and did not say anything.

French Education Minister Pap Ndiaye, speaking at the school, said about 90 students, including those who witnessed the bloody attack, along with some teachers, are receiving psychological help.

A minute of silence will be observed in all French schools Thursday afternoon in Lassalle’s honor. The teacher had worked at the school since 1997.

“There was no reason to think that such a terrible tragedy could take place here. This is a very calm school, known for its seriousness and serenity,” Ndiaye said.

With Post wires