Paris (AFP) - A Turkish teenager who stabbed a Jewish teacher with a machete on Monday in the southern French city of Marseille told police he had acted in the name of the Islamic State group, a prosecutor said.

The attack, which left the 35-year-old teacher with an injured shoulder and hand, occurred in broad daylight in the south of the city, prosecutor Brice Robin said.

The 15-year-old ethnic Kurd assailant rushed the victim from behind and stabbed him in the shoulder, then chased after him for a few metres (yards) until he fell, Robin said.

The victim fended off the assailant by kicking him and using the Torah he was carrying, which was damaged in the scuffle, as a shield, the prosecutor said.

The suspect "has the profile of someone who was radicalised on the Internet," Robin told a news conference.

"He claimed to have been acting for Daesh," he added, using the Arabic acronym for the Islamic State group.

"You get the sense that he does not have a full grasp of the fundamentals of Islam," he added.

The boy even admitted to investigators that he planned to arm himself and kill police as soon as he is released.

French President Francois Hollande, said "such acts are unspeakable and unjustifiable", vowing that authorities would continue to act "with the greatest firmness against anti-Semitism and racism".

The prosecutor said the attacker was a "good student" whose family had been unaware of his radicalisation.

"It appears there was a form of premeditation" with the intent of killing the victim because of his religion, Robin said.

The teenager, who will turn 16 next week, faces charges of "attempted murder on grounds of religion" and "defence of terrorism".

The teacher, who was wearing a skull cap, was on his way to work at the Franco-Hebraic Institute when he was attacked.

The incident follows another assault, north of Marseille, on November 18 in which three people shouting anti-Semitic obscenities and support for the Islamic State group stabbed a Jewish teacher, injuring him in the arms, legs and stomach.

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In a statement, the Jewish umbrella group CRIF said it was "urgent to get at the roots of this scourge, and those who... propagate it on the Internet".

It said French Jews were caught up in "a spiral of hatred that doesn't seem to want to stop."

France this weekend marked a year since jihadist attacks which left 17 people dead, including four people gunned down in a Jewish supermarket.