Riots and protests have broken out all across America since the St Louis County grand jury announced its decision not to prosecute Ferguson police officer Darren Wilson for the death of Missouri teenager Michael Brown. But the anger and sense of injustice has spread far beyond American soil. Last night, thousands of people marched through central London to express their disgust with the ruling.

Demonstrators gathered outside the US embassy to join a vigil for the murdered teenager, where a minute's silence was observed to remember victims of police brutality all over the world.

The crowd then set off for Parliament Square, making their way down Oxford Street with chants of "Hands up, don't shoot!" and "Killer police, off our streets!". Protesters spilled into the streets, bringing busy Christmas traffic in the shopping district to a standstill.  

The families of Mark Duggan and Sean Rigg also joined the protest. Tottenham local Duggan was shot dead at 29 by a police marksman in 2011, while Rigg died in Brixton police custody in 2008.

Duggan's aunt Carol told Russia Today: “Murder is not legitimate. No one should lose their child. Michael Brown has not got justice neither has Mark Duggan. The police are there to protect, not to kill our children.” 

After passing through Leicester Square, the march stopped outside Charing Cross police station. Police did not engage with the protesters and replaced their customary protest outfit of riot gear for non-threatening police caps and yellow caps. (Maybe they sensed the potential for a PR disaster, given the criticism of heavy-handed police tactics in Ferguson.)

Protesters were keen to drive home the parallels between police brutality in the US and in the UK.

"Things like this happen here as well, it's not all that far away," Onyeka, a 28-year-old filmmaker said. "People are really fed up because it keeps happening again and again and nobody gets held accountable. There are close to a thousand deaths in (UK) police custody and no convictions."

She added: "After the protest I went to Soho and I was standing around with a friend, and some police officers came up to him, hassled him, tried to ask him questions. It turned out they were just looking for some other black guy. So in reality, it hits quite close to home."

One of the most unusual sides to the protest (other than the hands-off police presence) was how young some of the marchers were. Many skewed under 20, with a few who looked no older than 15 years old. Onyeka noted that she had never seen such a young crowd of protesters before, barring the 2010 tuition fees protest. 

Activism group London Black Revs organised the protest in conjunction with NUS Black Students’ Campaign, Black Activists Rising Against Cuts (BARAC) and Defend the Right to Protest.

In a statement on their Facebook page, they issued an urgent call for transatlantic solidarity: "With the murder of yet another young black life going unpunished, we greet the news of police officer Wilson’s acquittal with disgust but unfortunately little surprise – if ever we needed a reminder, the justice system does not and cannot work in the interests black people.

"We extend our full support to those resisting police brutality in Ferguson and their right to defend themselves, and urge that black people on both sides of the Atlantic unify around and mobilise against the institutional violence that plagues our communities in the UK and the USA."

Head here for all our coverage of Ferguson.