A high school student, who reportedly suffered severe mental health issues, has allegedly stabbed a teacher to death in a classroom in southwest France.

A high school student has been arrested for allegedly stabbing a teacher to death while they were teaching a class, in the southwestern French town of Saint-Jean-de-Luz.

The incident took place on Wednesday morning in a classroom at Saint-Thomas d’Aquin, a private Catholic school, and both police and a local prosecutor are on the scene, the BBC reports.

French newspaper Sud Ouest said according to testimonies from students who fled the school in panic, a 16-year-old second-year student allegedly entered the classroom with a knife while the Spanish teacher - understood to be a woman in her fifties - was giving a class, and attacked her.

The victim was pronounced dead shortly after 11am, after a prolonged resuscitation attempt. Pupils from other classes were confined to their classrooms during the emergency response, the paper reported.

A government official, speaking anonymously because he was not allowed to discuss the issue publicly, said the first elements communicated by police suggest the alleged attacker had severe mental health issues.

People stand at the entrance of the Saint-Thomas dAquin middle school in Saint-Jean-de-Luz, south-western France, where a teacher died after allegedly being stabbed by a student (Photo by GAIZKA IROZ/AFP via Getty Images).

Bayonne prosecutor Jerome Bourrier said an investigation has been opened for suspected premeditated murder, and the student had been arrested and interviewed on Wednesday afternoon. The student was not previously known to police or justice services, Bourrier said. He declined to provide any further details while the investigation was ongoing.

The French education minister, Pap Ndiaye said in a Tweet he was extremely upset to learn of the death, and his thoughts were with the teacher's family, colleagues and pupils. Ndiaye, who had immediately travelled to Saint-Jean-de-Luz, said about 90 students - including some who witnessed the attack - and a number of teachers were being taken care of by a psychology unit.

A minute of silence will be held in all French schools on Thursday at 3pm, he said.

French government spokesperson, Olivier Véran, said the government would support educators across the country in the wake of the incident. “I can barely imagine the trauma that this represents at a local level, and more generally on a national scale," Le Monde reports.

French high school student arrested after teacher stabbed to death in classroom