Around 2,000 people have defied a ban to join a memorial rally in central Paris for a young black man who died in police custody, while marches took place throughout France to denounce police brutality.
Seven years after the death of Adama Traore, his sister had planned to lead an annual commemorative march north of Paris in Persan and Beaumont-sur-Oise on Saturday.
But fearful of reigniting recent unrest sparked by the police killing of 17-year-old Nahel Merzouk at a traffic stop near Paris, a court ruled the chance of public disturbance was too high to allow the march to proceed.
In a video posted on Twitter, Assa Traore, Adama's older sister, denounced the decision, saying "the government has decided to add fuel to the fire" and "not to respect the death of my little brother".
She instead attended a rally in central Paris's Place de la Republique to tell "the whole world that our dead have the right to exist, even in death".
"We are marching for the youth to denounce police violence. They want to hide our deaths," she said at the rally, also attended by several lawmakers.
"They authorise marches by neo-Nazis but they don't allow us to march. France cannot give us moral lessons. Its police are racist and violent," she said.
Around 30 demonstrations against police violence took place across France, including in the southern port city of Marseille and in Strasbourg in the east. Authorities in Lille banned a gathering.
The Paris rally had also been banned on the grounds that it could disrupt public order and a legal case has been opened against Assa Traore for organising the event, police said.
Youssouf Traore, another of Assa Tarore's brothers, was arrested on the fringes of the rally and then "transferred to hospital," march organisers said.
"The march went off peacefully, it was a success, we don't understand his arrest," they said. Paris prosecutors did not comment when contacted by AFP news agency.
Many at the rally shouted "Justice for Nahel" before calmly dispersing later in the afternoon.
The teenager's death on June 27 rekindled long-standing accusations of systemic racism among security forces, and a UN committee urged France to ban racial profiling.
The foreign ministry on Saturday disputed what it called "excessive" and "unfounded" remarks by the panel.
"Any ethnic profiling by law enforcement is banned in France," the ministry responded, adding that "the struggle against excesses in racial profiling has intensified".