Footage of the protests, attended by 5,000 football hooligans and far-right groups, showed topless white men drinking beer and chanting "England, England" while others attempted to punch police, throw bottles and let off fireworks.
A Black Lives Matter group in London called off a demonstration, saying the presence of counter-protesters would make it unsafe.
She drew a direct parallel between Floyd's death in the U.S. city of Minneapolis and that of her brother, and renewed her call for a full investigation into his killing.
Like many other companies, Apple has publicly spoken out on racism and the senseless killing of George Floyd.
He said he wanted to save the lives of young black boys who could have been targeted by "hooligans" if anything had happened to the white man.
A man, identified as far-right by members of the crowd, was lying injured on the ground and was rescued by members of an anti-racist protest group.
The protesters, many of which were middle-aged white men, claimed they were there to "protect" statues, after recent calls to remove them due to their colonial associations.
The Metropolitan Police said in a statement they had arrested five people for offenses including violent disorder and assault on police and that six officers had suffered minor injuries.
Statues of figures like Churchill were boarded up because, according to Mr Khan, right-wing groups were using the protection of them as a justification for heading to London for a standoff with BLM. Why is the Cenotaph attacked?
"We have reached out to our local black community and have had a very positive response, and have had many offers to speak on the day". However, it has also been widely reported that ordinary Brits who were simply concerned about the vandalising of statues of celebrated national figures turned up to protect them. "I am George Floyd", she said.
The picture was taken after hundreds of demonstrators, some of which belonged to far-right groups, clashed with police in Parliament Square.
Police used pepper spray and detained several people.
Australians marched Saturday amid warnings from state leaders to call off the events on fears of a second wave of coronavirus infections.
"It read: "[Shaw] explains there are agitators who misconstrue that fundamental principles of the Black Lives Matter movement - and in certain circumstances, intentionally repurpose them to amplify divisiveness".
"There have been people like my dad and Aunty Mingelly who have been pushing for change since they were my age - you know, that was 50 years ago", Jacinta Taylor, an organizer of the protest in Perth, told the rally.
"At the moment the scales are unfairly balanced and I just want things to be fair, for my children and my grandchildren".