Four US police officers shot during protests in Missouri

Four St Louis police officers were hit by gunfire late on Monday during violent protests over the death of a black man in police custody, hours after President Donald Trump vowed to use the US military to halt the spreading clashes.

Trump deepened outrage by posing at a church clutching a bible after law enforcement officers used teargas and rubber bullets to clear the way for him to walk there after he made his remarks in the White House Rose Garden.

Demonstrators set fire to a strip mall in Los Angeles, looted stores in New York City and clashed with police in St Louis, Missouri, where four officers were taken to hospital with non-life-threatening injuries.

"Officers are still taking gunfire downtown and we will share more info as it [becomes] available," St Louis Police said on Twitter.

Trump has condemned the killing 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 in Minneapolis on May 25, and has promised justice. But he said rightful protests could not be drowned out by an "angry mob".

"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 through an area that had been cleared by police to nearby St John's Episcopal Church, where 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, Michael Curry, was among those who criticized 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 White House said it was clearing the area before a curfew.

A few hours later, thousands of people marched through Brooklyn, shouting "Justice now!" while cars drove alongside, some drivers honking in support.

Television images showed crowds smashing windows and looting luxury stores along Fifth Avenue in Manhattan before the city's 11pm curfew. Mayor Bill de Blasio said the curfew would be moved to 8pm on Tuesday.

Two police officers were struck by a car at a demonstration in Buffalo, New York, on Monday night. Officials said the driver and passengers were believed to be in custody. It was not immediately clear whether the incident was intentional.

Reuters