An activist at a pro-Palestine march has been arrested just minutes after the event begun.
The Met Police detained a protester in central London on suspicion of inciting racial hatred.
Thousands of demonstrators are gathering at Park Lane to march from Marble Arch towards Piccadilly.
An arrest was made at the start of the protest after Nazi symbols were seen on a placard he was carrying.
The Met Police said they made the arrest just minutes after the march began
MET POLICE
The Met Police said on social media: “We have arrested a man on suspicion of inciting racial hatred near the start of the protest.
“Officers spotted him carrying a placard with Nazi symbols on it.”
A further two pro-Palestine protesters were arrested late in the march on suspicion of supporting a proscribed terrorist organisation.
Activists planning to take part in today's demonstrations were warned that police officers would take swift action against anyone breaking hate laws.
Senior Metropolitan Police officers said they were doubling down after several weeks of pro-Palestinian protests over the conflict between Israel and Hamas.
LATEST DEVELOPMENTS:
Protesters are marching from Marble Arch towards PiccadillyGB NEWSLeaflets were handed out to those in attendance today to warn that action would be taken against any banners, placards or chants that incite hatred.
Despite the police warnings, many of the placards on display included drawings of maps accompanied by the words “From the river to the sea”.
The phrase is contentious and is widely associated with an antisemitic chant which calls for the genocide of Jewish people.
Pro-Palestine activists argue it relates to the creation of a permanent Palestinian territory in the Middle East.
As many as 100,000 people are thought to be taking part in today's protest in London, which is demanding a permanent ceasefire in Gaza.
Fighting is currently paused between Israel and Hamas for a four day window while hostages are released as part of a swap deal.
Around 50 people held by Hamas are to be released in return for 150 Palestinians held in prison in Israel.
Those taking part in the march say the temporary ceasefire is not enough.
Protester Shaun, 33, from north London, said: “I don’t know what’s going to come from it, I don’t know if it’s positive, but I know full well that once this truce and temporary ceasefire are done they (Israel) are going to continue bombing and we’re going to be right back where we were, so I’m not holding my breath.
“We’ve seen this before – Israel reneges on its promises in the past, they renege on their promises now.”
More than 1,500 police officers have been deployed to help maintain order during the protests, with officers drafted in from outside the capital to help man the event.