A shooting broke out shortly before noon at rue d'Enghien near a Kurdish cultural center in the 10th arrondissement.
It left at least 3 dead and 2 injured in absolute emergency according to the prosecution.
The alleged shooter, in his 60s, was quickly arrested.
He is already known to the police for 2 attempted homicides.
The racist motive is retained according to the Paris prosecutor.
Journalist Marie Schuster is on site for France 24.