British lawmakers banned Palestine Action under anti-terrorism legislation in July after some of its members broke into a Royal Air Force base and damaged planes as part of a series of protests.

The group accuses Britain’s government of complicity in Israeli war crimes in Gaza.

Protesters, some wearing black and white Palestinian scarves and waving Palestinian flags, chanted “hands off Gaza”, and held placards with the message “I oppose genocide. I support Palestine Action”, video taken by Reuters at the scene showed.

Israel has faced accusations of genocide at the International Court of Justice and from human rights groups over its devastating military assault in Gaza.

The Reuters video showed demonstrators who had gathered in Parliament Square by the Houses of Parliament being carried away by police.

The crowd chanted “shame on you” at the police.

In a post on X, the police force said it had arrested 466 people for supporting a proscribed organisation.

It also arrested eight people for other offences, including five arrests for assaults on officers. The police said no one was seriously injured.

The ban makes it a crime to be a member of Palestine Action, carrying a maximum sentence of 14 years in prison.

The co-founder of the group, Huda Ammori, last week won a bid to bring a legal challenge against the ban.