More than 20 people have been arrested in London after a protest in support of the banned group Palestine Action, the Metropolitan Police has said. Pictures from the demonstration showed a small group holding placards reading "I oppose genocide, I support Palestine Action" in Westminster.

The protest group was officially classified as a terrorist organisation from midnight on Saturday after the measure received overwhelming support from MPs and following the failure of a last-minute legal challenge to delay it.

Roger Waters, the former Pink Floyd songwriter, is facing calls to be prosecuted after he declared his support for the banned terrorist organisation Palestine Action.