There was solidarity, sadness and anger in London on Wednesday as thousands of mostly young people gathered to protest against the death of George Floyd in US police custody. "I've seen the video going around on social media and it's genuinely a collective trauma," said Sharleen, 18, who joined the protest in Hyde Park. "All of my friends … since this, we've not felt the same. It's like this pain through all of us at the same time. "It goes from anger to sadness, it's just something you can't explain." Floyd, an unarmed African-American man, died on May 25 in Minneapolis after a white policeman knelt on his neck for nearly nine minutes. The incident, which was captured on camera, has sparked violent protests across the US and demonstrations around the world. In London, emotions were running high as protesters defied coronavirus restrictions on mass gatherings to march through the capital to Prime Minister Boris Johnson's office in Downing Street. The demonstrations were largely peaceful, with protesters chanting Floyd's name as they walked and passing vehicles beeping in support, but there were some heated clashes with police at Westminster. In one incident, protesters turned on an Australian news crew, heckling the journalists and chasing them away from the gates of Downing Street. Earlier in the day, Star Wars actor John Boyega gave a speech in which he often struggled to contain his emotion, expressing solidarity with Floyd and our "black brothers and sisters" in the US. "This is an important movement," student Lisa Ncuka, 26, told AFP. "Everybody should be here fighting for equality. It's not just a US problem, it's the whole world's problem and we need to come together and spread this awareness." There were placards demanding "Make racists afraid again", parodying US President Donald Trump's election campaign slogan, but also those proclaiming that "The UK is not innocent". "It may not be as bad here now but the racism we see in the UK is usually undercover," said Leyla, 20. "As a black woman living in London, I have seen too many times when police abuse their power by stopping and searching black people for no reason." "Enough is enough," read the banner held aloft by Sharlae, 18, who wore a mask to protect against coronavirus, like many in the crowd. "My friends, my family, my brothers, my father, my cousins should be able to walk the street without fear of being killed by police, when they are meant to protect us and keep us safe," Sharlae said. She said she had "millions of examples" of friends and family being stopped by police. "It's just something we have to deal with every day and we shouldn't," Sharlae said. Despite police reforms in recent decades, a 2015 study by educational charity the Runnymede Trust found "systemic and institutional racism persists" in British policing. The US police officer who knelt on Floyd's neck for up to nine minutes has been charged with second-degree murder and three colleagues face charges of aiding and abetting. The protesters expressed hope of justice, but several called for more ethnic minorities to be represented in the UK Parliament. "That's the only way to get changes," Leyla said. "It shouldn't be black versus whites, it should be everyone versus racism."