A French Jewish teenager, who attends the Toulouse school where Islamist gunman Mohamed Merah shot dead three children in March, has suffered a violent anti-Semitic attack on a train, French media reports said on Thursday.

The attack on Wednesday took place on a train travelling between Toulouse, which is in the south-west, and the city of Lyon in the south-east, Le Figaro newspaper reported, quoting an interior ministry statement.

"A teenager aged 17 wearing a distinctive religious symbol, who attends Ozar Hatorah school in Toulouse, was taken to task and insulted by two individuals," the ministry was quoted as saying.

He was then attacked near the toilets "by the same two individuals, who beat him up," the statement said, adding that the attack ended when a fellow passenger and train conductors intervened.

The victim filed a complaint with police in Lyon.

Ozar Hatorah school was the scene of the worst attack against Jews in France in 30 years when Merah shot dead three children and a rabbi at point-blank range as pupils were gathering for class on March 19.

Prior to that, he shot dead three soldiers, also in the Toulouse area.

Merah, who claimed to have been ordered by al-Qaeda to attack France, was shot dead during a police raid on March 22.

The school refused Thursday to comment on the train attack.

The interior ministry said it was determined to "combat any resurgence of the profound evil which is anti-Semitism" and warned the perpetrators faced "severe punishment."