Police in the French city of Lyon have banned any public gatherings on Sunday afternoon that might lead to unrest.
A nursery school in Carpentras was burned down overnight
It follows riots - the first in a major city centre - on Saturday when police used teargas to disperse youths throwing stones and attacking cars.
The ban, which covers the city centre and lasts until 1900 (1800 GMT), was issued under emergency laws introduced by the French government last week.
A similar ban in Paris ended on Sunday with no reports of unrest.
Police said the situation across France on the 17th consecutive night of riots was "much calmer" than previously.
"Things could calm down very, very quickly," national police chief Michel Gaudin told reporters.
More than 370 cars were burned overnight, down from 502 the previous night. A further 212 people were arrested.
In the southern town of Carpentras, a nursery school was torched and a burning car was pushed up to an old people's home, causing panic among residents.
A mosque in Carpentras had been firebombed on Friday, causing little damage but drawing condemnation from France's political and religious leaders.
A similar attack took place at Lyon's grand mosque on Saturday.
There were also disturbances in the cities of Toulouse and St-Etienne, and two riot police were injured.
The trouble in Lyon began at about 1700 (1600 GMT) on Saturday on Place Bellecour, where a large number of riot police were on duty as a preventative measure.
About 50 youths attacked market stalls and damaged vehicles, witnesses told Reuters news agency. Two people were arrested.
Interior Minister Nicolas Sarkozy blamed the Lyon violence on a "demonstration by anarchists", but did not elaborate.
Officials in Lyon and 10 towns to the east of the city earlier announced a curfew to bar unaccompanied minors from the streets over the weekend between 2200 (2100 GMT) and 0600 (0500 GMT).
The government last week declared a state of emergency in Paris and more than 30 other areas to help quell more than two weeks of unrest.
The measures allow local authorities to ban meetings "likely to start or fuel disorder".
Provides for state of emergency, regional curfews, house searches, house arrest
Public meeting places can be closed down and media, film and theatre showings may be controlled
Breach of curfew could mean two-month jail sentence
Paris had imposed the overnight ban after police reports of e-mails and text messages calling for "violent acts" in the city.
Meeting with Paris police on Saturday night, Mr Sarkozy repeated a pledge to throw out foreign nationals caught rioting.
"If you want to live in France with a residency permit, you have to abide by the laws... Immigration laws allow expulsions. I am the interior minister and I will apply the law," he said.
There was no sign of trouble, and peaceful demonstrations were allowed to go ahead with several hundred people rallying close to police headquarters in central Paris to protest against alleged discrimination against youths of immigrant origin.
The country's unrest was triggered by the deaths in the run-down Paris suburb of Clichy-sous-Bois of two youths, who were accidentally electrocuted at an electricity sub-station.
Locals said they were fleeing police but the police deny this.