Police have said they arrested 325 people on Saturday at a demonstration outside the US embassy in London against the proscription of Palestine Action.

In updated arrest figures released on Sunday, the Metropolitan police said 320 people were detained outside the building in Battersea, south London, for allegedly expressing support for an organisation banned under the Terrorism Act.

The arrests came ahead of Wednesday’s supreme court challenge to the ban on Palestine Action – the first direct action group to be proscribed under the Terrorism Act – which came into effect on 5 July last year.

Defend Our Juries, which has organised the mass civil disobedience campaign against proscription, said Saturday’s detentions took the total number of people arrested for allegedly supporting Palestine Action since the ban to 4,200.…