Target suspects
 
"I have never seen a police operation of this scope," Marie-Therese de Givry, a local prosecutor said at a news conference.
 
"I hope that the inhabitants will understand that we are there to re-establish order and peace," she said.

However Segolene Royal, the socialist candidate who lost out to Nicolas Sarkozy in the presidential election last year, criticised the raids as a "police operation for the media". 
Most of those detained are aged between 19 and 31, and have been known for previous violence, according to police.
 
Members of the Raid special police force, led the operation on about 10 apartment blocks in Villiers-le-Bel which was the focus of the unrest last November.
 
The area is populated largely by families of immigrant backgrounds.
 
Entrance buildings were guarded and groups of 30 police raided each apartment, according to the AFP news agency.
 
Police say they were looking for two gang leaders in particular who they believe organised attacks on police officers.
 
In one raid, about 100 police officers surrounded one building near a library and nursery that were burned down by rioters.
 
Suburb riots
 
Last year's violence erupted after two teenage boys were killed in a motorbike crash with a police car.
 
Police and local officials said it was an accident, but many residents were unconvinced.
 
Some officers were hit by gunfire and the clashes left 119 police officers injured, five seriously, according to justice ministry figures.
 
Tensions have run high in France's high-immigration suburbs since the country's worst civil unrest in decades in 2005.
 
Sarkozy this month launched an aid programme for France's poor suburbs, which has a high proportion of African immigrants and where youth unemployment is about 40 per cent.