Is this the start of a long-threatened explosion of unemployed, mostly North African, youth? Our correspondent went to Lille to test the temperature of the `quartiers difficiles' - the sink suburbs.
Hassan is sitting with a bunch of his friends in an unswept bar on the south side of Lille. All are in their early twenties. The topic of conversation is the impossible younger generation: the 13- to 18-year- olds, who have been throwing stones, even petrol bombs, at buses the length and breadth of France.
"The truth is they're lost, those kids, all lost. They believe in nothing. They expect nothing. Attacking buses is crazy but in France, you have to break something before anyone listens ... These kids are telling everyone: hey, look at us. We exist too."
Hassan is studying marketing: his dream would be to get a job in his chosen field, preferably in Lille. But he says, with a shrug, that he knows he has "no chance, because I'm an Arab".
"Our generation of kids in the quartier were told: work hard at school, to get a diploma. That was the way to get out of here. Some of us did, some didn't. But it didn't matter much. We're all stuck, just the same."
In his quartier, Hassan says he knows of only 25 kids who have passed "the Bac" (the Baccalaureat, the equivalent of A-levels). They are known as the "intellos" - the intellectuals. None of them has a job. "The younger kids, they see that and they think, `Why bother?' So they've given up. They're into car-stealing, drugs, guns."
It would be difficult to make a case that the south side of Lille looks worse than, say, parts of south Manchester. The streets are swept; the buses are smart and new; even the groups of mournful council blocks - "HLMs, habitations a loyer moderes" - look better maintained than their British equivalents.
What distinguishes - or disgraces Lille - is the intensity of the unemployment, especially youth unemployment: Lille is one of the youngest cities in France but more than 40 per cent of its young people have no work.
The south side of Lille typifies a feature of France - the doughnut of deprivation, and violence, around most large cities - which the 6 million tourists each year and the vast majority of French people prefer to forget. In Britain and the United States, towns tend to rot from the centre: in France, typically, the poor, the unemployed, the second- and third-generation immigrants, have been swept into the first ring of suburbs. In Paris this process is far advanced: in Lille, it is still going on.
Although in some way the French problem is less acute than in other countries (teenagers with guns is a worrying phenomenon, but still a new one), there are racial- political aspects of the French suburban pressure-cooker which are more scary than elsewhere. Notably, there is the baleful and opportunistic presence of the National Front. And because France is France - a country which justifies its large and interventionist state by pointing disapprovingly at the "social exclusion" of the "Anglo-Saxon economies" - the problems of the banlieues appear all the more damning.
One Muslim cleric in France has spoken of a "French intifada", but local activists say this winter's unrest is not religious, or even political. It is a scream of frustration, which has echoed, through publicity on television, from one city to the next. Rabah Aliouat, 32, a French-Algerian social worker said: "If you live at the end of the bus route, the bus becomes a symbol of the life, and wealth, of the city which you can't afford to enjoy. Even if you have the fare - or refuse to pay the fare - you have no money to do the things, or buy the things, the city offers ... Attacking buses becomes the symbol of the rage of the kids in the banlieue..."
There was a faintly cruel irony in the fact that the first bus attacks occurred in Lille, and its poorer, uglier twin-sister, Roubaix. Lille has been a laboratory for a new form of job- creation scheme for young people, devised by its deputy mayor, Martine Aubry, who is also the deputy Prime Minister.
The French government is committed to creating 700,000 similar jobs, at national level, over the next few years. The idea - similar to the Blair government's employment schemes for the young - is that the jobs should be socially useful and, in the long run, self-financing. In other words, Ms Aubry says that young people employed to organise sports events in the banlieues, or clean up the surrounds of council flats, will ultimately save money, and pay for their jobs, by reducing litter, vandalism and delinquency. Some of the people I met in the quartiers difficiles of Lille rejected the ideas as ill-conceived tinkering or as "cut-price social work", designed to help clever, middle-class kids, not the lost generation of suburban youth. On the other hand, I was toldof a former drug-dealer in Lille Sud who is now "delighted with himself" because he has a job: taking old people to the cemetery to visit the graves of their loved ones.
Farid Sellani, 24, is a Lille city councillor, an independent, who works with the Socialist mayor, and the former prime minister Pierre Mauroy. He is a second-generation French-Algerian, who was born in one of the "quartiers difficiles" of Lille Sud. ("I am Arab but I'm proud to be French.") He rejects suggestions that Lille is a two-speed town, which has dumped its poorer citizens. On the contrary, he says, Lille is leading the way in France in looking for solutions to these problems.
"But it is true that there is a sense of desperation, of anger, in the quartiers difficiles, which is much worse than eight or ten years ago. The mainstream politicians have lost touch with what is happening out there. The only people working the ground are the NF and a few independents like me."
Unemployment is the start of the problem, says Farid, and more jobs, and help in creating small businesses, are part of the answer. But the problem does not end there. "The kids of Arab origin are not the only ones out of work but it is, truthfully, much worse for them. They know that, even if there were jobs, their chances of getting one are much less than their French schoolmates. They know that, even if they could afford, to go to a night-club in town, they wouldn't be allowed in. I'm not entirely pessimistic. I believe things can be done or I wouldn't be in this job. But, as things are, France is storing up a great problem for itself."
Farid's brother Djemal, 27, is a film-maker, whose movies about the Lille Sud "quartiers difficiles", have won several prizes. Unlike his brother, he says, he is "very pessimistic".
"What you have now, with the younger kids is a collapse of all sense of citizenship. They live from day to day, to survive. They're attacking buses because there's nothing much else left. Its a kind of game. At any rate, if nothing is done, there is going to be an explosion a few years from now, which will make attacks on buses look like a game."