The MP Pamela Nash has tweeted a picture which from Portcullis House shows the scale of the Anonymous protest in Parliament Square.
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Finnish media say several people have been wounded in a stabbing in the city of Turku in western Finland.
Longer spells of rain across eastern Scotland with a weather warning in place until 6pm.
Julian Cadman, who is thought to have dual British-Australian nationality, became separated from his mother who was injured in the attack.