Authorities imposed curfews in the French Riviera cities of Nice and Cannes on Wednesday to prevent rioting, while the interior minister called for the deportation of foreigners convicted in the wave of unrest that has spread throughout France.

Looters and vandals defied a state of emergency with attacks on superstores, a newspaper warehouse and a subway station. Arson attacks continued after sundown, with a nursery school going up in flames in the southern city of Toulouse, RTL radio reported.

The unrest began Oct. 27 and has grown into a nationwide insurrection by disillusioned suburban youths who complain of discrimination and unemployment. Although many of the French-born children of Arab and black African immigrants are Muslim, police say the violence is not being driven by Islamic groups.

The extraordinary 12-day state of emergency, which began at midnight Tuesday, covered Paris, its suburbs and more than 30 other French cities from the Mediterranean to the border with Germany and to Rouen in the north — an indication of how widespread unrest has become.

Although rioting persisted in some places for a 13th night, car burnings fell by nearly half and reports of violence dropped. Nonetheless, looters and vandals defied the state of emergency with attacks on superstores in northern France and a newspaper warehouse and a subway station in the south.

The measures imposed in Nice also require some bars to close from 10 p.m. to 5 a.m. for the next 10 days, the regional government said.

The government toughened its stance against those involved in France's worst civil unrest since its 1968 student riots in Paris.

Interior Minister Nicolas Sarkozy, who previously inflamed passions by referring to troublemakers as "scum," said 120 foreigners have been convicted for roles in the violence, and he called on local authorities to expel them.

"I have asked regional prefects to expel foreigners who were convicted — whether they have proper residency papers or not — without delay," he said during a National Assembly session.

That such extraordinary measures were needed, however, has fueled national introspection about France's failure to integrate its African and Muslim minorities seen as a key reason behind the rioting.

In the past, Sarkozy has vowed that France would expel Muslim prayer leaders who preach hatred and strip them of their citizenship. More than three dozen imams whose preachings are violent or do not conform with French values have been expelled since 2003, he said last month.

Far-right leader Jean-Marie Le Pen told The Associated Press his National Front party has been "submerged" with prospective members and supportive e-mail since the rioting erupted.

Le Pen described the recent violence as "just the start" of conflicts caused by "massive immigration from countries of the Third World that is threatening not just France but the whole continent."

Le Pen said people with immigrant backgrounds who commit crimes should be stripped of their French nationality and sent "back to their country of origin."

The emergency decree invoked a 50-year-old security law that dates to France's colonial war in Algeria that empowers officials to put troublemakers under house arrest, ban or limit the movement of people and vehicles, confiscate weapons and close public spaces where gangs gather.

Nice, Cannes and Antibes were among 21 municipalities in the Alpes-Maritime region where curfews were imposed. Minors are forbidden from being outdoors between 10 p.m. and 5 a.m. without adult supervision.

There have been no direct clashes between youths and police in the Riviera but unrest that began in the area Friday had persisted in some towns for four nights.

Arsonists struck a warehouse used by Nice-Matin newspaper in the town of Grasse, national police spokesman Patrick Reydy said. A total of 161 cars have been burned about half in the Nice area and nine buildings damaged across the Riviera region. Youths looted and set fire to a furniture and electronics store and an adjacent carpet store in Arras, in the north, he said.

Separately, in Normandy, the Seine-Maritime department had announced curfews until Tuesday for minors in four towns, including Rouen and Le Havre.

During late Tuesday through early Wednesday, youths torched 617 vehicles, down from 1,173 a night earlier, national police spokesman Patrick Hamon said. Incidents were reported in 116 towns, down from 226.

Police made 280 arrests, raising the total to 1,830 since the violence erupted 13 nights ago.

National Police Chief Michel Gaudin said an additional 1,000 officers were deployed overnight, bringing the total to 11,500. He attributed the drop in attacks to police sweeps and cooperation from community groups.

"The arrests are bearing fruit," Interior Ministry spokesman Franck Louvrier said. "It's clear there has been a significant drop, but we must persevere."

Christian Gaillard de Lavernee, head of the national civil security brigade, said firefighters responded to 30 percent fewer calls overnight than the previous day. In some towns, concerned residents have banded together to keep overnight watch on public buildings and to patrol their neighborhoods, armed only with fire extinguishers.

Riot police fired tear gas to disperse youths throwing gasoline bombs in Toulouse, and rioters exploded an unoccupied bus with Molotov cocktails in the town of Bassens, near Bordeaux. No injuries were reported.

Officials were forced to shut down the southern city of Lyon's subway system after a firebomb exploded in a station late Tuesday, a regional government spokesman said. No one was hurt. Transport officials said bus and subway service will be halted at 7 p.m. each day at least until Sunday as a precaution.

Prime Minister Dominique de Villepin, detailing the measures to parliament Tuesday, said riot police faced "determined individuals, structured gangs, organized criminality." Police say rioters have been using mobile phone text messages and the Internet to organize arson attacks.

The northern city of Amiens, central Orleans and Savigny-sur-Orge, and the Essonne region south of the capital were imposing curfews for minors, who must be accompanied by adults at night. Two cars burned in Amiens overnight despite the curfew, compared with six a night earlier, police said.

Curfew violators face up to two months in jail and a $4,400 fine, the Justice Ministry said. Minors face one month in jail.

The state-of-emergency law was drawn up to quell unrest in Algeria during its war of independence from France. It was last used in December 1984 by the Socialist government of President Francois Mitterrand against rioting in the French Pacific Ocean territory of New Caledonia.

The recent unrest started as a localized riot in a northeast Paris suburb angry over the accidental deaths of two teenagers of Mauritanian and Tunisian descent who were electrocuted while hiding from police in a power substation.