Britain will not surrender its flag to those who wish to use it as a symbol of violence, fear and division, Sir Keir Starmer has said.

The prime minister said the flag represents "our diverse country" and he will not allow people to feel intimidated on "our streets because of their background or the colour of their skin".

His comments come after more than 150,000 people took to the streets of central London for a "Unite the Kingdom" march organised by far-right activist Tommy Robinson, and about 5,000 took part in a counter-protest, coordinated by Stand Up To Racism.

Earlier, Business Secretary Peter Kyle said marchers were "demonstrating freedom of association and freedom of speech".

The prime minister said on Sunday afternoon, "People have a right to peaceful protest. It is core to our country's values.

"But we will not stand for assaults on police officers doing their job or for people feeling intimidated on our streets because of their background or the colour of their skin.

"Britain is a nation proudly built on tolerance, diversity and respect. Our flag represents our diverse country and we will never surrender it to those who use it as a symbol of violence, fear and division."

Police say 26 officers were injured on the day - including four who were seriously hurt - with 24 people arrested.

For most of Saturday afternoon, central London was filled with thousands of people waving mainly Union Jacks as well as St George's flags. Some Scottish Saltires and Welsh flags were also seen.

Speaking about the protests, Kyle said on Sunday with Laura Kuenssberg, moments like these were "klaxon calls" for those in power to redouble their efforts to address the big concerns people have, including on immigration.

"What worries me most is the divisions in our society and other societies and other democratic societies... it's not even the left and the right at the moment," he told the programme.

"There are figures such as Tommy Robinson that are able to touch into a sense of disquiet and grievance in the community in our society," he said.

The "small minority" who had committed violence would be held accountable, he told the programme.

Tech billionaire Elon Musk spoke to protesters on Whitehall via videolink, telling them to "fight back" or "die". He also referred to massive uncontrolled migration and called for a change of government in the UK.

Kyle criticised some of Musk's comments as "totally inappropriate".

Robinson, whose real name is Stephen Yaxley-Lennon, addressed crowds directly at the march, where he criticised politicians for "parroting" his ideas.

A huge policing operation was put in place for the protests this weekend, with about 1,000 Met officers deployed and an extra 500 from other forces, including Leicestershire, Nottinghamshire and Devon and Cornwall, drafted in.

Assistant Commissioner Matt Twist said: "There is no doubt that many came to exercise their lawful right to protest, but there were many who came intent on violence."

The protest was largely peaceful on Saturday lunchtime, but as the afternoon continued, tensions flared.

The Met said some officers had been attacked while trying to keep the two groups apart, and dozens of officers were injured, including four who were seriously hurt.

The number of protesters joining the march, organised by Robinson, became too large to fit into Whitehall, police said, and confrontation took place when officers tried to stop them encircling counter-protesters.

Mounted police officers used batons to push back the crowds, and officers were kicked and punched, the Met said.

Three of the 24 people arrested were women, and the rest were men, while the youngest and oldest people detained at the protest were aged 19 and 58, respectively, the force said on Sunday.

Several people were arrested for more than one offence.

The force added officers were working to identify other people involved in the disorder with a view to making further arrests.