LONDON — More than 100,000 people descended on Britain’s capital on Saturday for one of the country’s largest far-right rallies in decades.

The “Unite the Kingdom” rally was organized by Tommy Robinson, a convicted fraudster with a violent criminal record, and attended by billionaire Elon Musk via video link. Amid a sea of flag-waving and soccer-style chanting from large crowds that exceeded expectations, violent clashes with police led to dozens of arrests.

It came amid a surge of nationalism in the U.K., with a far-right party topping the polls, and the murder of American conservative activist Charlie Kirk — an assassination Robinson used to mobilize support in the run-up to the event.

Image: "Unite The Kingdom" Rally And Counter Rally By Stand Up To Racism Takes Place In Central LondonCrowds gathering in London on Saturday ahead of the far-right “Unite the Kingdom” rally.Ben Montgomery / Getty Images

Robinson — whose real name is Stephen Yaxley-Lennon — has long inspired rallies of mostly white, mostly male followers campaigning against Islam and immigration.

He billed Saturday’s event as Britain’s “largest free speech festival.”

In a video link to the rally, billionaire Musk called for a change of government in Britain and railed against the “woke mind virus” and “uncontrolled immigration.”

“My appeal is to British common sense, which is to look carefully around you and say: ‘If this continues, what world will you be living in?’” said Musk, who has previously spoken out in support of Robinson and other far-right causes across the world. “Whether you choose violence or not, violence is coming to you. You either fight back or you die, that’s the truth, I think.”

Musk labelled the U.K. a “tyrannical police state” in 2024, saying the country was on the verge of “civil war” following days of right-wing riots after three young girls were killed in a knife attack at a Taylor Swift-themed dance party.

Protesters at the "Unite The Kingdom" rally.Supporters of Tommy Robinson wave flags on Saturday.Carlos Jasso / AFP – Getty Images

Saturday’s demonstration saw “disorder, violence directed at officers and 26 officers injured,” London’s police force said, adding that it had made 25 arrests.

Police were “assaulted with kicks and punches,” and Unite the Kingdom demonstrators threw “bottles, flares and other projectiles” as they tried to enter a “sterile area” created to separate them from a smaller counterprotest organized by Stand Up to Racism.

Footage posted by the force showed police with riot shields pushing back a crowd of protesters.

Kate Hopinks and Tommy Robinson.Katie Hopinks and Tommy Robinson attend the “Unite the Kingdom” rally on Saturday in London.Ben Montgomery / Getty Images

Robinson had told attendees not to wear masks, drink alcohol or be violent.

“It’s not a time for riots,” he said in a video on X. “It’s not a time for violence. It’s a time where you come and you stand proudly for your country.”

The Metropolitan Police told NBC News they estimated there were 110,000 to 150,000 people in attendance at the Unite the Kingdom protest, “significantly exceeding the estimates of organizers,” and 5,000 at the counterdemonstration.

British police had urged Muslim Londoners not to alter their plans, despite a record of “anti-Muslim rhetoric and incidents of offensive chanting by a minority at previous marches.”

Protesters clash with police at the "Unite The Kingdom" rally.Protesters clash with police officers in London on Saturday.Christopher Furlong / Getty Images

“There have been some suggestions that Muslim Londoners should change their behavior this Saturday, including not coming into town,” said Metropolitan Police Cmdr. Clair Haynes, who is in charge of the public order policing operation in London. “That is not our advice. Everyone should be able to feel safe traveling into and around London.”

With five Premier League soccer matches taking place in the capital the same day, more than 1,600 officers were deployed, police said.

“The football lads are coming from everywhere,” said Robinson, who was released from prison in May after being jailed for contempt of court in October.

In a Thursday video to supporters about Kirk, who was fatally shot Wednesday while speaking at an event at a university in Utah, Robinson referred to “the bastard who has murdered him, or the organization, the corporation or the government it is that has killed him.”

“In honour of @charliekirk11 & in honour of freedom on the 13th we march,” he wrote in a separate post on X.

Hundreds of people gathered at a vigil in London on Friday night to mourn Kirk, 31, a father of two.

Protesters drape themselves in flags.Protesters drape themselves in flags in London on Saturday.Christopher Furlong / Getty Images

Britain’s far right has been emboldened as Reform UK, a party led by Trump ally Nigel Farage, tops the polls. Farage recently said he would deport 600,000 people if he wins the next election.

In recent months, English flags have increasingly appeared on lampposts, crosswalks and apartment windows — seen by some as patriotism and by others as linked to soccer hooliganism and racism.

A counterprotest was led by leftist lawmakers Zarah Sultana and Diane Abbott.

Protesters at the "Unite The Kingdom" rally.A demonstrator holds a placard as he sits on the head of one of the lions of Westminster Bridge in London on Saturday.Joanna Chan / AP

Footage posted by the group on X showed hundreds of people gathered chanting, “Refugees are welcome here.”

Nearly 900 people, many of them older than 60, were arrested under counterterrorism legislation at a London demonstration last weekend against the ban on the group Palestine Action.

The British government banned Palestine Action — which describes itself as a direct action movement that uses disruptive methods — as a terrorist organization in July, putting it alongside Al Qaeda and ISIS. Membership or support is now a criminal offense punishable by up to 14 years in prison.

That extends to acts such as wearing clothing, carrying items or holding placards that could reasonably be seen as showing affiliation with the group.