The home secretary has said the toppling of a statue in Bristol by anti-racism protesters was “utterly disgraceful”.
There were wild cheers as the statue of Edward Colston was yanked off its plinth and later sprayed with paint and dumped in the harbour.
“Sheer vandalism and disorder is completely unacceptable,” said Priti Patel – who added that it would distract from the protesters’ cause.
Avon and Somerset Police said they were investigating after a “small group” committed criminal damage.
Colston made his fortune off the back of the slave trade in the 17th century and helped build schools, churches and homes for the poor in Bristol.
A petition to remove the statue – which had stood for more than 120 years – had received 11,000 signatures.
The Bristol protests were attended by an estimated 10,000 people and there were no arrests, said police.
The demonstration was one of a number around the UK this weekend sparked by the killing of George Floyd in America nearly two weeks ago.
The vast majority have been peaceful, with thousands turning out to support the Black Lives Matter movement.
There were some scuffles in central London on Sunday evening as a few hundred protesters tried to enter King Charles Street, near the Foreign Office and The Treasury.
Bottles were thrown and police drew their batons to keep the crowd from pushing through the stone arches.
The situation calmed down after about 20 minutes but protesters and police remained at the scene.
In Parliament Square, graffiti was scrawled on the statue of former prime minister Sir Winston Churchill, with spray paint used so the name plate read Churchill “is a racist”.
Earlier on Sunday, a large crowd descended on the US embassy in London, with masses of people snaking down the road holding cardboard signs and chanting slogans such as “no justice, no peace”, “George Floyd” and “get Boris out”.
Free masks, gloves and hand gel were being given out.
Other demonstrations took place in Edinburgh’s Holyrood Park and St Peter’s Square in Manchester.
On Saturday, 14 police officers were hurt when violence broke out in one part of central London.
Police on Whitehall were pelted with bottles and officers on horseback were forced to charge at the crowds.
One of the injured police was taken to hospital after riding into a traffic light on her horse. Twenty-nine people were arrested.
The home secretary said the violence – yards from The Centotaph and Downing Street – was “shameful”.
She called the killing of Mr Floyd “appalling” and echoed concerns that protesters could be helping spread the coronavirus.
While some who turned out had face masks on, social distancing appeared to have been disregarded by many.
Health Secretary Matt Hancock told Sky’s Sophy Ridge on Sunday programme “it is undoubtedly a risk” that the number of coronavirus cases would rise following the protests.
“I support very strongly the argument that is being made by those who are protesting for more equality and against discrimination, but the virus itself doesn’t discriminate,” said Mr Hancock.
“Gathering in large groups is temporarily against the rules precisely because it increases the risk of the spread of this virus.”
Protests over the death of Mr Floyd have continued around the world since his death in Minneapolis on 25 May.
The 46-year-old was killed when a police officer handcuffed him and knelt on his neck for almost nine minutes despite him repeatedly saying he could not breathe.
Hundreds of thousands marched in cities across the US on Saturday, with events passing off overwhelmingly peaceful – including in Washington DC where tear gas and rubber bullets were fired earlier this week.