The traditional village ball 18 minutes outside the city ended in the traditional way: young men fighting outside.

What made it different were the flashing knives.

Three young men were rushed to the hospital early in the morning on Nov. 19. One, the 16-year-old captain of a local rugby team, died en route from a stab wound to his heart.

What might have been considered a local tragedy for the residents of Romans-sur-Isère, a working-class city 60 miles south of Lyon, quickly became a national story for one reason: race. The victim was a white teenager from the countryside, while many of the suspects were of North African ancestry and from La Monnaie, a rough city neighborhood notorious for drug dealing.

Almost immediately, far-right supporters, politicians and the right-wing media pounced on the case as proof that France’s traditional values were under threat from immigrants, and their descendants, who they say have refused to assimilate.

Nourished by this interpretation, 50 to 100 ultraright nationalists later descended on the city to avenge what they characterized as an anti-white murder. Armed with iron bars and baseball bats, they chanted, “Islam get out of Europe.”

For others, it was the far right’s growing strength and audacity that posed the biggest threat to the country and their own safety. Many residents of La Monnaie said they now stayed at home, fearing they would be targeted for wearing hijabs or for their North African roots.