Prefect office official, Nicolas Lavielle told local media that four men and a youth aged 15 were arrested over the two nights of clashes between residents and police.

French Interior Minister Manuel Valls has vowed to bring to justice those responsible for torching a school and sports center and for firing live ammunition at police officers.

The group was detained on the basis of thermal images taken from a police helicopter during rioting that caused six million euros ($7.3 million) worth of damage to public buildings.

Police said they did not make any arrests during the unrest earlier this week for fear of inflaming the already volatile situation.

"The investigation is ongoing," a police spokesperson said. "These are the first arrests."

One of the five men arrested was suspected to be the group's ringleader and has been charged with inciting a rebellion, a serious crime under French law, punishable by a prison term of up to 10 years if the perpetrator was armed with a weapon at the time of the offence.

Rioters torched public buildings during clashes with police

The clashes erupted on Sunday after police stopped a motorist for dangerous driving. Residents of Amines' northern quarter say this week's violence was the result of years of police harassment of youth in an area where two out of three young people under 25 are unemployed.

The unrest highlights the challenges facing socialist President Francois Hollande who was elected three months ago on a promise to ease tensions between law enforcement and youths, something which spiralled out of control under former president Nicolas Sarkozy.

jlw /ipj (Reuters, AP, dpad)