Two schools in Grigny, south of Paris, were set alight in the latest attacks and a preschool was badly burnt in the Essone region.
Arsonists set ablaze around 100 cars in the Ile-de-France region around Paris.
Since the violence began, more than 2,000 cars have gone up in flames.
The rioting continues to spread, with flare-ups in the cities of Lille, Rouen, Rennes, Toulouse and Marseilles.
Much of the rioting has happened in poor suburbs with a high immigrant population and high unemployment.
Muslim community leaders have accused French Interior Minister Nicolas Sarkozy of fanning the flames with his tough rhetoric on "zero tolerance" law and order policies.