An assailant Friday was found to have decapitated a history teacher in France who had recently shown cartoons of the Prophet Mohammed in class, police said, adding that police had shot the suspected killer dead.

A French anti-terrorism prosecutor has opened an investigation into the slaying for murder with a suspected terrorist motive, the prosecutor's office said. The gruesome incident occurred in the town of Eragny, in the Val d’Oise region northwest of Paris.

A police official said the suspect, armed with a knife and an airsoft gun was shot to death by police about 600 meters from where the teacher was killed. The teacher had been threatened after opening a discussion "for debate" about the caricatures, the police official told The Associated Press.

The official could not be named due to not being authorized to discuss ongoing investigations.

It was the second incident since the opening of an ongoing trial regarding the massacre perpetrated against satirical newspaper Charlie Hebdo in January 2005.

The newspaper previously sparked much debate in France over the right to caricature the prophet, Muhammed – depictions of whom are forbidden in Islam – and drew indignation from the country's Muslim community.