French police staged  protests for a second day Friday over claims of racism in their ranks, assailing top officials for failing to defend the force against allegations amplified by US unrest over the death of George Floyd.

Several dozen officers blocked traffic in a wildcat march down the Champs-Elysees avenue in Paris, carrying a banner proclaiming: "No police, no peace!"

On Thursday, officers in Lille, Marseille and other cities threw their handcuffs, armbands and other equipment on the ground while standing in formation, with many shouting for the resignation of Interior Minister Christophe Castaner.

Castaner infuriated officers this week with a pledge of "zero tolerance" for police racism after some 20,000 people massed at the Paris courthouse on June 2 in an echo of the Black Lives Matter protests in America.

He also said police would no longer be allowed to use chokeholds to detain suspects, a move derided by many officers as an unfeasible concession that could make their jobs more perilous. "The police are not racist... they save people's lives no matter the colour of their skin," Fabien Vanhemelryck, head of the Alliance union, told journalists on Friday.

Patrice Ribeiro of the Synergie union charged: "We're being spit on, and why? Because at the highest level of the government they're afraid of a noisy minority."

Castaner was to meet police representatives Friday after talks with others on Thursday. "It's not just the interior minister... the president must make sure the police are respected," Vanhemelryck said. New protests against alleged police violence and racism have been called for Saturday in Paris and other cities.

Some police unions have threatened to carry out only minimal duties, since France forbids strike action by law enforcement agents. President Emmanuel Macron could address the heightened tensions in a televised speech to the nation on Sunday.

'Progress, not invitations'

Protesters alleging police violence have rallied around the case of a young black man, Adama Traore, who died in police custody in 2016 in a Paris suburb. Traore's sister has long demanded that the officers who apprehended him be charged with murder.

The family contests expert reports exonerating the officers, including one las month that said Traore died of heart failure possibly brought on by underlying health conditions. An investigation into his death is under way, with prosecutors announcing this week that two witnesses have been called to give testimony in July.

Traore's family refused to meet Justice Minister Nicole Belloubet this week to discuss the case, saying it wants "judicial progress, not invitations". French police have often faced accusations of excessive violence, with some incidents caught on video sparking widespread outrage.

On Wednesday, the country's human rights ombudsman announced an investigation into the arrest of a 14-year-old boy last month that left him with severe facial wounds and broken teeth. He claimed officers kicked him. Of nearly 1,500 complaints against law enforcement officers last year, half were for alleged violence, according to the force's oversight body.

The public mood was further inflamed this month when media outlets published postings from a private Facebook group where police members repeatedly used racist and sexist terms and mocked victims of police brutality.