Spreading urban unrest - with arsonists striking from the Mediterranean to the German border - reached central Paris for the first time Sunday after 10 days of violence and more destruction of cars, buildings and symbols of French authority. The crisis, which began as an outburst of anger among Muslims living in suburban Paris housing projects, reached new intensity with at least 900 cars torched across the country overnight, despite repeated calls for calm and massive policing to halt the unrest. Police said 32 cars were set afire in Paris as the violence moved from poor suburbs into the capital for the first time. Post offices, municipal buildings, provincial police stations and even nursery schools were targeted by Muslim arsonists to the north, south, east and west of Paris. Police made 186 arrests overnight nationwide. France, with some 5 million Muslims, has the largest Islamic population in Western Europe.