More than 300 people have been arrested during a protest supporting the banned Palestine Action group outside the US embassy, police have said.

Hundreds of people gathered at Nine Elms in London on Saturday, with many holding signs reading phrases such as: “I oppose genocide, I support Palestine Action.”

The Metropolitan Police said on Sunday that 325 arrests were made. The force added on social media that 320 of them were for “expressing support for a proscribed organisation under the Terrorism Act”.

At least 4,000 arrests have been made in relation to the group, which was proscribed in July 2025.

The UK Supreme Court is due to review Palestine Action’s ban under terrorism legislation, after the group’s co-founder was granted permission to appeal it.

The Home Office has said that it will robustly defend against the appeal.

Officers on Saturday made arrests into the evening, taking people to police vans for transfer, to the applause of many protesters, some of whom chanted: “Free, free Palestine.”

In some instances, officers had to carry demonstrators who refused to walk.

Retired lawyer Charles Allison – who was taken by police in the afternoon – had travelled from Cumbria to participate. He said he feared for people’s civil liberties, which he said were “being devalued and watered down”.

“I hope the Supreme Court justices – they won’t necessarily be influenced by it [the protest] – but I hope that they will take a long-term view of what is happening in this country and decide that the proscription was unlawful, as I believe it was,” the 75-year-old said.

David Bolden, another protester awaiting arrest called the ban an “absurd law”.

Defend Our Juries, which has been co-ordinating a series of protests over the ban, said the number of people detained this weekend took the total over 4,000 arrests since the group was proscribed, calling it “truly dystopian”.

According to Home Office figures seen by the BBC, 3,630 arrests were made in the year ending June 2026. Along with the 134 people arrested outside Westminster Magistrates Court earlier this year and those on Saturday brings the total up to 4,089.

The BBC has contacted the Met to confirm any figures it might hold.

Amnesty International UK has criticised the arrests and called for the government to drop the proscription of Palestine Action.

Defend Our Juries called the arrests “unjust” and an assault on free speech.