Thousands of pro-Palestinian protesters marched through central London on Saturday, after a government warning that anyone waving a Palestinian flag could face arrest in certain circumstances.
The route, which was expected to end at Whitehall outside the Cabinet Office at about 3pm, is covered by a Section 12 order.
That means anyone “participating in or associated with the 'Palestine Solidarity Campaign' protest must not deviate from the route below or they may be subject to arrest”, police said.
As they gathered, protesters waved Palestine flags and supportive placards and chanted, with police and community support officers stationed nearby.
Husam Zomlot, Palestine's ambassador to the UK, thanked the protesters for attending, praising the peaceful gathering.
Addressing the crowd near Downing Street, he said: “Thank you for your solidarity. I cannot begin to tell you how much this means to us, the Palestinian people, that even now, when we feel isolated, abandoned, that so many of you are prepared to come out in support of Palestine, in support of justice, in support of law, in support what is right, in support of peace.
“Make your voices heard like you are doing now with pride and dignity, peacefully with respect for public order.”
More than 1,000 officers were deployed by the Metropolitan Police for the march, which saw supporters gather to express solidarity with Palestine as the conflict between Israel and Hamas, the group that rules Gaza, continues to escalate.
Pro-Palestinian rallies also took place in Manchester, Edinburgh in Scotland and elsewhere in the UK.
Deep divisions in public opinion have resurfaced in the UK since war broke out. There has also been shock at a letter to police from the Home Secretary Suella Braverman that said in some circumstances waving a Palestinian flag could be deemed support for Hamas, proscribed as a terrorist organisation by the UK since 2001.
Sebastian Shehadi, 29, who is taking part in the march, told The National there are Palestinian flags “everywhere” among the protesters.
He criticised France's decision to ban pro-Palestinian protests, adding: "In the name of anti-Semitism we cannot be Islamophobic and racist ourselves.
"We have seen what happened in France, where it is now illegal to hold the national symbol of Palestine. Can you imagine? The country that is renowned for protest and revolution, France.“
"A lot of people are saying here isn’t it crazy that this freedom march, this peaceful march, would be illegal in France.”
He said only the police intervention he had seen was to prevent people from covering their faces.
Mr Shehadi estimated there were “tens of thousands” of people taking part in the march, adding: “It feels like the Stop The War marches we have seen for Iraq. It’s is a big one.
“We are snaking all the way down from the BBC to Piccadilly Circus. It’s covering quite a large ground,” added Mr Shehadi, who is British-Lebanese.
Fellow protester and friend Omar Hamaoui said those taking part were there to stand by people in Gaza and show the world they would not “be silenced”.
“We are also doing it in a peaceful manner,” he added.
“There was obviously a worry, looking at the global media, whether it’s France or Germany [where protests have been banned].
"But everyone here has shown it’s a peaceful protest. There is no anti-Semitism. There are no feelings of hatred.“
"We are a democratic country. We should be able to voice our opinion and stand up for people.”
Pro-Palestinian protesters gathered outside the BBC's Broadcasting House in Portland Place before the start of the march at midday.
In a statement shared on X, formerly known as Twitter. before the march on Saturday, police said: “We’re acutely aware of the emotions, the fear and the anxiety in our communities across London as a result of the conflict between Israel and Hamas.
“We’re expecting thousands of people to come to the capital for a march for Palestine and I want to assure people that we have a really comprehensive and significant policing plan in place to ensure the safety of people attending and to deal with criminality and hate crime should that occur.”
The government had previously warned that waving a flag in support of Hamas or other proscribed organisations at the protest would be an offence.
The Home Secretary, Suella Braverman, also suggested this week that waving Palestinian flags could in some contexts be seen as illegitimate.
However, Dame Lynne Owens, deputy commissioner of the Metropolitan Police, gave more clarity when she said expressing support for Palestinians, including waving Palestinian flags, would not automatically be considered a criminal offence by anyone taking part in the march.
The BBC's headquarters in London was earlier daubed in red paint, following criticism over its editorial stance against describing Hamas militants as terrorists.
Police said the incident has so far not been linked to any protest group.
The march came as Palestinians began a mass exodus from northern Gaza after Israel's military told them to evacuate ahead of an expected ground invasion.
The UN, human rights groups and others have been among those expressing deep concern about the impact of Israeli action on civilians, as the death toll continues to grow amid airstrikes and a siege on the territory.
Amid concerns about the scale of the Israeli response, Prime Minister Rishi Sunak said on Friday that the country has "every right to defend itself" from Hamas attacks but stressed that civilian safety must be "paramount in our minds".
Police and the government have noted a spike in UK anti-semitic crime and incidents since the Hamas assault, while officers in Sussex, southeast England, arrested a 22-year-old woman on Friday suspected of having made a speech backing Hamas.
A banned terrorist organisation in Britain, its members, or those found guilty of inviting support for it, can be jailed for up to 14 years under UK law.