Police Sunday reported more gunfire in the French city of Grenoble, hit by two nights of riots, and arrested four men for attempted homicide after they allegedly shot at officers.

The four were seized in a dawn raid in the working class neighbourhood of La Villeneuve after two nights of unrest in which rioters exchanged gunfire with police and torched shops and scores of cars.

The riots broke out after a 27-year-old man, Karim Boudouda, was shot dead by police on Thursday when he fired at them in a chase after he allegedly robbed a casino. A public prosecutor concluded police fired in self-defence.

Police said the four were held for attempted homicide after firing bullets at police during the worst of the rioting early on Saturday. They did not identify those arrested or give their ages.

Police had already arrested at least 11 other people, some for carrying weapons such as a baseball bat and a knife. No one was reported hurt in the unrest.

Interior Minister Brice Hortefeux visited the scene in the southeastern city nestled in the French Alps on Saturday and pledged to quickly restore order.

"There's no future for hoodlums and delinquents because in the end the public authority always wins," he said.

District police official Brigitte Julien told a news conference on Sunday that more bullets were fired at police on Saturday night. That night was judged calmer overall, with about 15 cars burnt compared to 60 on Friday.

Car burnings are not rare in some of France's deprived suburban districts, which suffer from tension between the largely immigrant populations and police.

In October 2005, weeks of rioting broke out in suburbs across France, sparked by the death of two youths who were electrocuted when they entered an electricity installation as they ran away from police.

Saliya Boudouda, the mother of the man killed on Thursday, said she would lodge a complaint against police.

"They messed up, the cops," she told AFP by telephone. "I am going to see the prosecutor and lodge a complaint. I'm going to take this very far."