President Donald Trump on Monday vowed to use the US military to halt protests over the death of a black man in police custody, before law enforcement officers fired rubber bullets and tear gas to clear demonstrators and allow the president to walk to a church and pose for pictures.

But as darkness fell hours after the president’s remarks in the Rose Garden of the White House, violence erupted for a seventh night. Demonstrators set fire to a strip mall in Los Angeles and looted stores in New York City.

“Mayors and governors must establish an overwhelming law enforcement presence until the violence has been quelled,” Trump said. “If a city or state refuses to take the actions that are necessary to defend the life and property of their residents, then I will deploy the United States military and quickly solve the problem for them.”

Following his address Trump walked from the White House through the area that had been cleared for him to nearby St. John’s Episcopal Church, where he clutched a Bible as he posed for pictures with his daughter, Ivanka, and US Attorney General William Barr.

The presiding bishop of the Episcopal Church diocese in Washington DC, Michale Curry, was among those who criticised Trump’s use of the historic church for a photo opportunity.

“In so doing, he used a church building and the Holy Bible for partisan political purposes,” he said on Twitter. The church suffered minor fire damage during protests on Monday night.

The security forces that moved against protesters at the White House included National Guard military police, Secret Service, Department of Homeland Security police as well as District of Columbia police. The White House said it was clearing the area ahead of a curfew.

A few hours after the Washington fracas, thousands of people marched through the streets of Brooklyn, shouting “justice now!” while cars drove alongside, some drivers honking in support.

Television images showed throngs smashing windows and looting luxury stores along Fifth Avenue in Manhattan, one of the cities toniest shopping districts, before the city’s 11 pm curfew. Mayor Bill de Blasio said the curfew would be moved to 8 pm on Tuesday.

Two police officers were struck by a car at a demonstration in Buffalo, New York, on Monday night. Erie county’s chief executive Mark Poloncarz said the driver and passengers of the vehicle were believed to be in custody. It was not immediately clear if the incident was intentional.

Fire in Hollywood

In Hollywood, dozens of people were shown in television images looting a drug store after the front door was smashed. Windows were shattered at a nearby Starbucks and two restaurants before suspects scattered as police arrived.

Anti-police brutality marches and rallies, which have turned violent after dark each night over the last week, erupted over the death of George Floyd, a 46-year-old African American who died after a white policeman pinned his neck under a knee for nearly nine minutes.

A second autopsy ordered by Floyd’s family and released on Monday found his death was homicide by “mechanical asphyxiation”, or physical force that interfered with his oxygen supply. The report says three officers contributed to his death.

The Hennepin County Medical Examiner later released autopsy findings that also called Floyd’s death homicide by asphyxiation. The county report said Floyd suffered cardiopulmonary arrest while being restrained by police and that he had arteriosclerotic and hypertensive heart disease, fentanyl intoxication and recent methamphetamine use.

Derek Chauvin, the 44-year-old Minneapolis police officer who kneeled on Floyd, was arrested on third-degree murder and second-degree manslaughter charges. Three other officers involved in the arrest have not been charged.

Floyd’s death was the latest case of police brutality against black men caught on videotape and prompting an outcry over racism in US law enforcement.

It reignited simmering racial tensions in a politically divided country that has been hit hard by the coronavirus pandemic, with African Americans accounting for a disproportionately high number of cases.

Dozens of cities across the United States remain under curfews not seen since riots after the 1968 assassination of Martin Luther King Jr.