French police arrested at least 25 people in a major pre-dawn operation Monday north of Paris, targeting the suspected ringleaders of riots last year.
Nearly 1,000 elite forces took part in the operation in and around Villiers-le-Bel, 20 kilometres (12 miles) north of the capital, said sources close to the investigation.
Police initially spoke of 17 arrests but justice official Marie-Therese de Givry told the press later that 25 people had been detained.
Violence flared up in the area in late November after two teenagers died in a motorbike crash with a police car.
During three nights of the worst rioting, some officers were hit by gunfire and the clashes left 119 police officers injured, five of them seriously, according to justice ministry figures.
In December, police handed out leaflets in the area calling for witnesses to the shots fired.
The leaflets offered rewards of up to several thousand euros for information and said sources could remain anonymous.
President Nicolas Sarkozy said immediately after the riots that everything would be done to find those responsible for the attacks.
"That cannot rest unpunished, it is an absolute priority," he said.
Tensions have run high in France's high-immigration suburbs since the country's worst civil unrest in decades in 2005. (AFP)
French police arrest 25 over Paris riots