What, other than pure soccer hooliganism, could have prompted this? Vanity Fair's Julian Sancton explains:
There is a significant Algerian contingent in France, and a majority of the Algerian soccer team’s players are French-born.
The riots are the latest soccer-related tremor to rock France, which is already reeling from its own humiliating World Cup performance, made all the more disgraceful by the embarrassing behavior of the Gallic squad. As the team returns home, President Nicolas Sarkozy has ordered an official appraisal of the state of French soccer. (If this seems excessive, remember that that Congress ordered special hearing to address the issue of steroids in baseball, and George W. Bush mentioned it in one of his State of the Union addresses.)