The teacher killed in a suburb of Paris in an Islamist terror attack has been named as Samuel Paty, Sky News has confirmed.

Paty, 47, was "assassinated,'' France's president has said.

The history teacher, who is said to have discussed images of the Prophet Muhammad with his pupils, was beheaded, it has been reported.

The suspected attacker was shot dead about 600 meters from the scene, according to the AP news agency.

It happened on a street in Conflans Sainte-Honorine, northwest of the French capital, at about 5:00pm local time.

Visiting the scene, Emmanuel Macron called it a "cowardly attack,'' saying that the man was a "victim of an Islamist terrorist attack" and was killed because he "taught the freedom of expression, of believing and not believing.''

The president said France would "protect and defend" its teachers.

According to Le Parisien newspaper, the attacker was an 18-year-old man of Chechen origin, who was carrying a knife.

Sky's Adam Parsons, who is at the scene, says he was not thought to be on any watchlist.

He is believed to have been shot after he refused to put down his gun.-Photo: Sky News

A video of his last moments is thought to feature the sounds of the gun being fired, followed by a volley of shots as he was killed.

A gun was found at his side. Reports say it was an airsoft gun that fired plastic pellets.

The country's anti-terror prosecutor earlier called the incident a stabbing, but both the Reuters and AP news agencies said police sources told them the victim was decapitated.

History teacher Samuel Paty was decapitated by a Islamic terrorist, a Chechen refugee.

Teacher decapitated by Islamic terrorist named as Samuel Paty