People gather for the national Justice For All march against police violence in Washington DC
People gather for the national Justice For All march against police violence in Washington DCReuters

Thousands of protestors gathered on the streets of Washington DC, New York and other US cities on Saturday to voice their anger at the killings of black men by police.

Over 40,000 demonstrators are expected to march in what organisers have called a National Day of Resistance. They are demanding justice for Michael Brown, an unarmed black teenager who was shot dead by a white police officer.

"We stand in solidarity with social justice activists from all over the country who call for an end to racial profiling and police brutality," NAACP president and chief executive Cornell William Brooks said in a statement.

Protestors will also march for Eric Garner, who died in a choke hold in July. A grand jury declined to indict the white police officer implicated in his death, Daniel Pantaleo, less than two weeks after a Missouri grand jury also decided not to indict Darren Wilson, the officer who shot dead Brown.

A grand jury declined to indict the white police officer implicated in his death, Daniel Pantaleo, less than two weeks after a Missouri grand jury also decided not to indict Darren Wilson, the officer who shot Brown.

They will also march for Tamir Rice, a 12-year-old black child shot dead on a playground by a white Cleveland police officer, who says he believed the boy's toy gun was real.

Also remembered is Akai Gurley, an unarmed 28-year-old man who was shot dead by a policeman in the stairwell of a Brooklyn public housing complex, in what New York police commissioner Bill Bratton said was an apparent accident involving a "total innocent".

Reverend Al Sharpton is leading the Justice for All March in Washington DC, together with families of those killed in recent encounters with police.

"We need more than just talk – we need legislative action that will shift things both on the books and in the streets," said Sharpton.

Among the marchers are the parents of Michael Brown, the mother of Tamir Rice, the mother and widow of Eric Garner, and the parents of Trayvon Martin, a 17-year-old shot dead in February 2012 by George Zimmerman, who undertook armed patrols of his neighbourhood in Florida. It will be the first time the group of bereaved relatives have come together in protest.

In New York City, the Millions March began in Washington Square Park. "It's open season on black people now," said New York march co-organiser Umaara Elliott.

"So we demand that action be taken at every level of government to ensure that these racist killings by the police cease."