London’s Metropolitan Police had refused ministerial requests to block the event, saying they did not have indications that there would be serious violence, straining relations with the government.

The scuffles between police and the far-right counterprotesters took place close to the Cenotaph war memorial earlier on Saturday, where some of the counterprotesters chanted: “We want our country back.”

Bottles were later thrown at police by members of right-wing groups in a separate incident in Chinatown, about a mile north of the war memorial, police said.

Arab and Muslim leaders slam Israel, seek swift end to ‘barbaric’ war

Police said in a statement late on Saturday that they had arrested 126 people so far, most of whom were right-wing protesters who formed part of a group several hundred strong which police said included football hooligans.

“The extreme violence from the right-wing protesters towards the police today was extraordinary and deeply concerning,” Assistant Commissioner Matt Twist said, adding that a knife and knuckle-duster were found during searches.

“They arrived early, stating they were there to protect monuments, but some were already intoxicated, aggressive and clearly looking for confrontation. Abuse was directed at officers protecting the Cenotaph, including chants of ‘You’re not English any more.’″

While the much larger pro-Palestinian rally did not see physical violence, the senior officer said small groups had broken away from the main march, and about 150 people wearing face coverings had fired fireworks which struck officers in their faces, leading to arrests.

Investigations into a small number of hate crime and support for proscribed organisation offences were also ongoing, Twist said.

Sunak called for the police to take a tough line.

“All criminality must be met with the full and swift force of the law,” he said in a statement late on Saturday. “That is what I told the Met Police Commissioner on Wednesday, that is what they are accountable for and that is what I expect.”

Skirmishes between police and right-wing protesters continued throughout the day, with police in riot gear using batons to try to contain protesters who threw bottles.

London Mayor Sadiq Khan and Scotland’s first minister, Humza Yousaf, said Braverman had inflamed tensions and emboldened the far-right by accusing the police of favouring “pro-Palestinian mobs” before the event.

Police said more than 300,000 had joined the pro-Palestinian rally, while organisers put the figure at 800,000.

Some marchers chanted “From the river to the sea, Palestine will be free”, a rallying cry viewed by many Jews as antisemitic and a call for Israel’s eradication.

Others carried banners reading “Free Palestine”, “Stop the Massacre” and “Stop Bombing Gaza”.

Since Hamas’s assault in southern Israel on October 7, there has been strong support and sympathy for Israel from Western governments, including Britain’s, and many citizens. But the Israeli military response has also prompted anger, with weekly protests in London demanding a ceasefire.

‘Peace only on paper’: Gaza war sharpens Arab world’s grievances against Israel

Deputy Assistant Commissioner Laurence Taylor, leading the police operation, had said counterprotesters were likely to include football hooligans, and police were “likely” to have to use force at some point against “pockets of confrontation”.

About 1,850 police officers, including some brought in from other regions, have been drafted in to keep the peace, with 1,375 on Sunday, when a national service of remembrance took place at the Cenotaph led by King Charles, senior royals and political leaders.

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Where China stands on the Israel-Gaza war

Where China stands on the Israel-Gaza war

Braverman, an increasingly outspoken right-winger, has done little to quell tensions, by accusing police of being more sympathetic to so-called left-wing protests than others.

Support for Palestinians is a long-standing policy of the British political left.

The government was also at odds with the Metropolitan Police this week, with ministers calling for the march to be banned, sparking concern over political interference in operational matters.

Sunak said he would hold Met Police commissioner Mark Rowley “accountable” for his decision to allow the demonstration to go ahead.

Rowley has said, however, that it does not meet the threshold for requesting a rare government order to stop it going ahead.

Also on Saturday, about 21,000 people took part in a pro-Palestinian rally in Brussels, police said, many chanting slogans such as “Free Palestine” and demanding a ceasefire in the Gaza Strip as they marched peacefully through the city.

“What is happening right now in Gaza is beyond devastating,” one demonstrator said, carrying a poster that read “Ceasefire now!” in Dutch.

In Paris, France, several thousand demonstrators, including some left-wing lawmakers, marched with Palestinian flags and banners to call for a ceasefire in Gaza.

Additional reporting by Reuters, Associated Press