French riots: Amiens buildings torched in clashes
14 August 2012 Last updated at 16:14 BST
Buildings and cars were set alight as youths and police clashed during the night in the northern French city of Amiens.
Sixteen officers were injured in the clashes with up to 100 youths, some of whom threw fireworks and projectiles, police said.
President Francois Hollande has vowed to restore order but the BBC's Christian Fraser in Paris said that the situation seemed to be getting "progressively worse".
He suggested that there was a "tinderbox atmosphere" in suburbs of French cities suffering from high youth unemployment and poverty.