Cauchemar Blanc (English: White Nightmare) is a 1991 short film by Mathieu Kassovitz, based on the comic written for the screen by Moebius.
[1] One winter's night in France, four racists, J.P., Berthon, Barjout, and René, set out to assault a local Arab man.
The four follow him to a vacant parking lot outside of an apartment building, but the car they are in suddenly starts smoking, causing them to crash into a phone booth.
When an Afro-French denizen accuses J.P. of lying, he becomes angered and begins insulting him, only to discover that the black man is a police commissioner.
When René begins showing off his "skills" with nunchucks, one of the sticks detaches and hits Berthon in the head, knocking him out cold.