Leading article: Violence born of social division

The scale and duration of the rioting in France's cities has now become a cause of serious concern to the whole country. This weekend saw no let-up in the violence. And the phenomenon is spreading rapidly. On Saturday night, there was vandalism in cities all over France, from Marseille to Strasbourg. More than a thousand vehicles were torched and many public buildings, including schools, were petrol-bombed by youths. Cars were torched in La Place de La Republique in central Paris. How long, many are asking, before the riots spill over from the deprived suburbs into the more affluent parts of France's cities?

It is unclear how much organisation there has been behind the rioting. The speed with which the disorder has spread from city to city is likely to point to a degree of co-ordination. Copycat rioting is not a sufficient explanation in itself. It is reasonable to presume rioters have been using their mobile phones and internet access to maximise the impact of their demonstrations. But the suggestion that there is some sort of Islamist agenda behind the rioting is harder to sustain. The areas where the violence has been taking place are predominantly Arab and African, but not exclusively so. Many of the rioters are not Muslims. That is not to say that repressive actions by the French authorities could not result in a rise in support for Islamism in these areas. The near tear-gassing of a mosque by police some nights ago seems to have stoked tensions.

France's leaders have responded poorly to the crisis. The interior minister Nicolas Sarkozy and the Prime Minister Dominique de Villepin - who are both competing for the 2007 presidential election - have turned the rioting into a political football. M. Sarkozy's tough talk has been seen as posturing to gain the favour of right-wing opinion. His talk of "pressure cleaning" the "scum" from the violent estates was not well judged. M. de Villepin has been silent, but has encouraged others to speak out against his rival's handling of the situation.

But there are more profound causes of these nights of destruction. Heavy-handed - often brutal - policing of France's deprived estates must take some responsibility. It was the suspicion that the police allowed two boys to die in an electrical substation in a Paris suburb that sparked the rioting. Economic deprivation is also responsible. The violence is concentrated in areas where unemployment is twice the national average.

One thing is certain: the rioters are only adding to the suffering of their communities. The weekend's marches in the Paris suburbs protesting against the violence is a sign that the situation will not be allowed to continue forever. The riots will end - but the deep social divisions will remain. At least, until France gives serious consideration to what it needs to do to eradicate them.