George Floyd’s brother has pleaded for peace in the streets and New York City has imposed a curfew as the US braces for more violence amid a coast-to-coast outpouring of rage over police killings of black people.

After six straight days of unrest set off by the death of Mr Floyd in Minneapolis, a new routine is developing: residents waking up to neighbourhoods in shambles, shopkeepers sweeping up broken glass and taking stock of ransacked stores, and police and political leaders weighing how to address the boiling anger.

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“We are a country that is scared,” said Sam Page, county executive in St Louis County, Missouri, where the city of Ferguson has been synonymous with the Black Lives Matter movement since the 2014 death of Michael Brown, a black 18-year-old, during a confrontation with a white officer.

“We are country that is angry. And we are a country that is holding out for the promise of justice for all.”

New York imposed an 11pm to 5am curfew on Monday as the nation’s biggest city tried to head off another night of destruction, state governor Andrew Cuomo and city mayor Bill de Blasio said.

The limitation on 8.6 million people’s movements — on top of restrictions already imposed because of coronavirus — came as the mayor and governor condemned the outbreaks of violence, but also criticised some police actions as fuelling protesters’ rage.

While many of the demonstrations around the country have been peaceful protests by racially diverse crowds, others have descended into violence, despite curfews in many cities and the deployment of thousands of National Guard troops in at least 15 states.

On Sunday, protesters hurled rocks and petrol bombs at police in Philadelphia, set a fire near the White House in Washington and were hit with tear gas or pepper spray in Austin, Texas, Atlanta and other cities.

Seven Boston police officers were taken to hospital, and in some cities, thieves smashed their way into stores and ran off with as much as they could carry.

Police officers and National Guard soldiers enforcing a curfew in Louisville, Kentucky, killed a man early on Monday when they returned fire after someone in a large group shot at them, police said.

In Indianapolis, two people were reported dead in bursts of violence over the weekend, adding to deaths recorded in Detroit and Minneapolis.

In hard-hit Minneapolis, thousands marching on a closed motorway were shaken when a tractor-trailer rolled into their midst. No serious injuries were reported, and the driver was arrested on suspicion of assault.

On Monday, Mr Floyd’s brother Terrence appeared at the junction in Minneapolis where his brother died to appeal for peace.

“I understand you’re upset,” he told the crowd through a megaphone. But he said civil unrest and destruction is “not going to bring my brother back at all. It may feel good for the moment, like when you drink, but when you are done, you’re going to wonder what did you do. Let’s do this another way”.

Mr Floyd died last week after a white Minneapolis police officer pressed his knee against the handcuffed black man’s neck for several minutes, pinning him to the pavement, while he gasped that he could not breathe.

Officer Derek Chauvin has been charged with murder, but protesters are demanding that three other officers at the scene be prosecuted. All four were fired.

Racial tensions around the US have also been running high because of the arrest of two white men in May in the February shooting death of black jogger Ahmaud Arbery in Georgia, and after police in Louisville shot Breonna Taylor dead in her home in March.

Even as police in some places tried to calm tensions by kneeling or marching in solidarity with protesters, officers elsewhere were accused of the very type of harsh treatment at the heart of the unrest.

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In Fort Lauderdale, Florida, an officer was suspended for pushing a kneeling woman to the ground during a protest, and two Atlanta officers were fired after smashing in the window of a car and using a stun gun on its two occupants.

In Los Angeles over the weekend, a police SUV accelerated into several protesters in a street, knocking two people to the ground.

In New York, the police commissioner said about six incidents were being investigated by the department’s internal affairs bureau, including a weekend confrontation in Brooklyn in which two police vehicles appeared to plough through a group of protesters.

In another incident, an officer pointed a gun at protesters, drawing condemnation from the mayor.

The scale of the protests has rivalled the historic demonstrations of the civil rights and Vietnam War eras. At least 4,400 people have been arrested.