Three soldiers on patrol outside a Jewish community centre on the French Riviera were attacked on Tuesday by a man who was only last week expelled from Turkey, a security source said.
The knife-wielding assailant left two of the soldiers lightly injured and was immediately arrested, a police source said.
The attack took place in broad daylight in Nice as the troops were guarding the centre under reinforced security measures introduced after last month's deadly jihadist attacks in Paris.
A security source involved in the investigation told AFP the man was expelled from Turkey last week and had been interrogated by French intelligence services upon his return.
One soldier was injured in the arm and the other in the face. Both were being treated by medical personnel at the scene.
Anti-terrorist prosecutors in Paris have taken charge of the investigation, a judicial source told AFP.
There was no immediate indication why the man carried out the assault.
"Shortly after 2:00 pm (1300 GMT), while three soldiers were patrolling in front of a Jewish site... a passer-by violently attacked one of them with a large knife, aiming at his face and neck," said a police source.
Several sources close to the investigation named the man arrested as Moussa Coulibaly.
However, there was "apparently" no link to Amedy Coulibaly, who killed a policewoman and four Jewish shoppers in a kosher supermarket during the Paris attacks that left a total of 17 people dead.
President Francois Hollande has since vowed to combat what he called "unbearable" rising anti-Semitism in France, after figures showed anti-Jewish acts doubled over the past year.
France has deployed some 10,500 soldiers outside "sensitive" sites in the wake of the attacks, notably outside Jewish and Muslim places of worship, schools and media outlets.
France is home to Europe's largest Jewish population, estimated to be between 500,000 and 600,000, as well as its largest Muslim community, estimated at around five million.
Source: AFP