A source in the Metropolitan Police told Sky's policing analyst Graham Wettone that about 50 arrests have been made.

There were violent scenes when a a large mob of people carrying St George's flags was seen walking along Embankment and shouting "England 'til I die".

A line of police attempted to stop them from reaching Whitehall but the group pushed through, with some shouting "let's have them" as officers responded with batons.

Bottles were also thrown at police by the counter-demonstrators, many of whom were wearing masks.

The confrontation happened shortly before the Armistice Day two-minute silence, when hundreds of people gathered at the Cenotaph to commemorate the UK's war dead at 11am.

The service passed off without incident.

Stephen Yaxley-Lennon, also known as Tommy Robinson, the founder of the English Defence League, had called for his supporters to mass in the capital.

He was among the crowds along with former GB News presenter Calvin Robinson.

The Met Police posted on X, formerly Twitter: "While the two minutes' silence was marked respectfully and without incident on Whitehall, officers have faced aggression from counter-protesters who are in the area in significant numbers."

The force said it "will use all the powers and tactics available to us to prevent" the counter-protesters from confronting the main march calling for a ceasefire in Israel's war against the militant group Hamas.

There were later further clashes in Chinatown when missiles were thrown at police, while a "large group" were detained following trouble at Westminster Tube station.

It is understood the group of about 100 people were being held under powers to prevent a disturbance.

Of the 50 arrests, police confirmed one suspect was detained on suspicion of possession of a knife.

The main pro-Palestinian demonstration, expected to be attended by more than 500,000 people, had drawn criticism from the prime minister and home secretary because it coincided with remembrance events.

Suella Braverman had faced accusations of inflaming tensions after accusing the police of "playing favourites" when they resisted pressure to ban the march calling for a ceasefire in the Israel-Hamas conflict.

In the face of condemnation and calls for Rishi Sunak to sack her, Mrs Braverman subsequently expressed her "full backing" for the Metropolitan Police at a meeting with Commissioner Sir Mark Rowley.

But in the wake of the trouble, London mayor Sadiq Khan wrote on X: "The scenes of disorder we witnessed by the far-right at the Cenotaph are a direct result of the home secretary's words.

"The police's job has been made much harder.

"The Met have my full support to take action against anyone found spreading hate and breaking the law."

Scottish First Minister Humza Yousaf said: "The far-right has been emboldened by the home secretary. She has spent her week fanning the flames of division. They are now attacking the police on Armistice Day.

"The home secretary's position is untenable. She must resign."

More than 1,000 police officers have been drafted in from outside forces to monitor the protests, with the Met saying 1,850 officers will be on duty on Saturday and 1,375 on Sunday.

The route of the pro-Palestinian demonstration was from Hyde Park to the US embassy in Vauxhall, south of the Thames.

Many of those taking part carried Palestinian flags and placards with slogans such as "free Palestine" and "end the siege", while chanting "ceasefire now".

Even though the march was not intended to go near the Cenotaph, an exclusion zone was in place for Whitehall and other nearby areas, while the monument will have a dedicated 24-hour police presence until after Remembrance events on Sunday.

Additional protest powers are also in place enabling officers to search anyone in a designated area for weapons, and remove face coverings.

A dispersal zone in force for key central London locations including Trafalgar Square and Piccadilly Circus.

A key concern of the Met was to avoid clashes between marchers and counter-protesters.

Deputy Assistant Commissioner Laurence Taylor said: "Our job is to ensure that we police without fear or favour, that we balance the rights of everybody, be that protesters, counter-protesters, or people living or coming into London.

"And our job this weekend is to ensure that people are kept safe, and that is what my focus is on."

Meanwhile, protests at a number of London train stations have been banned, with prohibition orders in place at Waterloo, Victoria and Charing Cross between 10am and 11pm on Saturday.

Transport Secretary Mark Harper, who approved the move, said: "Armistice Day is a moment of solemn national reflection in remembrance of those who have given their lives in service of our country. It's important that people can use our rail network to safely travel, free from intimidation."