France banned large gatherings in Lyon on Sunday after police clashed with youths in the country's second city, but police said violence was waning in other areas under emergency measures such as curfews.
Regional authorities imposed the central Lyon ban after police used tear gas on Saturday to break up the first disturbances in any city centre since frustrated youths began rioting in France's impoverished suburbs on October 27.
A fire bomb was also thrown at a mosque in Lyon, a city of 1.2 million people, but did not explode, police said.
The ban on rallies was imposed until 7 pm (1800 GMT) on Sunday and a curfew on minors was due to go into force from 10 pm until 6 am for the second consecutive night.
It is not clear why unrest has worsened only now in Lyon. But, like Paris, it has poor and dreary neighbourhoods and violence has erupted before in its suburbs.