Masquerouge said :
An explanation for this is that in Marseille the population is globally more mixed than in other towns, resulting in less ghettos, and ths, less angry people living in these ghettos.
The direct answer could be : "And they have the highest Front National -Xenophobic Right- in France". They are further than other french cities on the path to integration; a path through difficulties that tend to make xenophobic vote grow on the short term. That's why Marseille, Toulon don't experience to much problems.
In France there is the Republic, whereas in some countries there is a King, the bank, a Queen, or a Bush (

). It means complete tolerance of each other's nature if they respect the laws of the Republic.
France -medias, politics, regions, associations- never qualifies anybody with their religion, politic views or anything else (Color of skin, I'm ashamed so much americans do that all the time !!!!!!).
I work half a mile South of the spoted riots and live north of the area, I fully support the victims. It's about 15 years old childs on the Nov-1 Nov-11vacation... The mass majority of the French think that the republican values needs to be applied as allways. It means stopping the violence, understanding their reasons and make things change.
Nobody on earth will convince any republican that making mass repression in a social conflict isn't making him grow bigger; And in the first place : that stupidly throwing discriminatory affirmations is an issue. It's not about race since there aren't any to be considered before or after the human one.
BTW, about the very few angry americans : France is condeming it's Chief General in Côte d'Ivoire for trying to hide the kill by some of it's soldiers of a criminal afew month ago. It's war in Côte d'Ivoire, and he's now out of business. I don't remember hearing such discipline in the Great Coalition's operating regions.