Thousands of people have taken to the streets of the British capital on Wednesday to protest the US police killing of George Floyd.
Protesters in London carried signs reading "Black Lives Matter" and "I can't breathe".
Floyd, an African-American, died on May 25 in Minneapolis after a police officer handcuffed him and knelt on his neck for eight minutes, including three in which he was unconscious. In a video released after his death, he can be heard calling for help and pleading with officers that he couldn't breathe.
His death has sparked protests across the US which have since spread to Europe. Between 20,000 and 40,000 protesters gathered in Paris, France, on Tuesday evening, while 5,000 marched through Amsterdam, in the Netherlands on Monday.
Asked about the protest during the government's daily COVID-19 briefing, Prime Minister Boris Johnson described himself as "appalled and sickened" by what happened to Floyd.
"Racism and racist violence have no place in our society," he stressed.
"I do think people have a right to protest to make their feelings known about injustice," he continued, adding: "I would urge people to protest peacefully and in accordance with social distancing rules."
"Black lives matter but we must fight this virus as well," he said.
Ahead of the London protest, UK police leaders said in a statement that they "stand alongside all those across the globe who are appalled and horrified by the way George Floyd lost his life".
"Officers are trained to use force proportionately, lawfully and only when absolutely necessary. We strive to continuously learn and improve. We will tackle bias, racism or discrimination wherever we find it," they added.
But Black Lives Matter UK rejected the statement, saying instead that "officers regularly use disproportionate and unlawful force, even when (as recent video showed) it is not absolutely necessary."
"Policing is oppressive and racist," they added.