KEY POINTS:
After a two-year gap, youth violence in France's rundown suburbs has erupted anew, prompting appeals for calm and warnings of a crackdown.
But there is also soul-searching as to why the country is failing to integrate the children of its immigrant generation.
Young men, many from France's Arab and African minorities, have fought running battles with riot police in the northern Paris suburb of Villiers le Bel, torching scores of cars, shops, a library and a kindergarten.
Sporadic incidents have erupted in other suburbs on the rim of Paris and Toulouse.
The spark for the unrest was the death of two youngsters, aged 15 and 16. The sons of African immigrants were racing around their housing estate on Monday on a a souped-up 80cc motorbike that is unlicensed for use on public roads. They crashed into a police car and were killed.
The smash started rumours that police caused the accident and had fled, leaving the children to die on the road.
More than 120 police have been injured in the riots, 10 by shotguns. "When people use guns against police, we are on the brink of a catastrophe," said the police union Unsa.
Prime Minister Francois Fillon angrily promised a crackdown: "Those who shoot at policemen, those who beat a police officer almost to death are criminals and must be treated as such."
Youth workers and mayors have been warning for two years of brooding tensions in the low-income, high-rise towns that ring Paris, Lyon, Marseille and other cities.
These suburbs face common, entrenched problems, beginning with their architecture - isolated, windswept concrete estates, designed by urban planners of the 1960s and 1970s as dormitory towns for immigrant labourers.
Transport in these towns is poor and unemployment rates are twice the national average, reaching 40 per cent in some areas. Gangs, drugs, theft, vandalism and assault are commonplace, but policing is often scant or heavy-handed.
"What happened in Villiers le Bel could just as well happen in many other towns in the area," says Dominique Lefebvre, a Socialist who is mayor of Cergy, northwest of Paris.
"What you are seeing is the end result of years of discrimination and social and territorial segregation."
"French society has allowed powderkegs to emerge that could be up in flames at any time," says Claud Dilain, mayor of Clichy-sous-Bois. "Those who are surprised by what has happened now know nothing about the suburbs. Nothing has been done to tackle the scale of the problem."
In 2005, three weeks of rioting left hundreds injured and 10,000 vehicles and 400 buildings torched.
The latest unrest throws down the gauntlet to President Nicolas Sarkozy, who was elected this year partly because of his tough stance on the 2005 violence.
Sarkozy, deeply unpopular with alienated suburban young people, has tried to soften his image by appointing three women of immigrant descent to his Cabinet, including Fadela Amara, a leftwing women's rights campaigner, as Housing Minister.
Amara, who herself lives in a tower block, is scheduled to unveil a national plan in January aimed at boosting education, youth employment and transport links in the suburbs. But there are fears that her scheme could be wrecked if the violence deepens or Sarkozy takes an iron-fisted approach.
"There is no magic wand," says Nadine Morano, speaking for Sarkozy's party, the Union for a Popular Movement. "It's going to take us a generation to transform things in these neighbourhoods."
RIOT OF DISQUIET
Villiers-Le-Bel
Youths rampaged for a third night setting more cars on fire in and around the Paris suburb where the trouble first erupted and 22 youths were taken into custody. About 1000 officers and a helicopter patrolled trouble spots in and around Villiers-le-Bel.
Toulouse
In the southern city, 20 cars were set ablaze. Fires at two libraries were quickly brought under control.
The Fallout
In total, 120 police officers have been injured, 10 of them by buckshot and pellets. Eight people were convicted yesterday in fast-track trials and sentenced to three to 10 months in prison. The use of firearms - rare in the 2005 riots - added a dangerous dimension.AP
