Mobs of anarchists ran amok in London storming the world famous Ritz hotel and smashing doors and windows on Saturday.
Now there are fears this was just a rehearsal and that the anarchists plan to disrupt next month's royal wedding of Prince William and Kate Middleton.
Nearly half a million demonstrators marched through London on Saturday to protest budget cuts. But a contingent of extremists broke off and attacked high end stores where the royals shop.
They fought running battles with police. Others took over Trafalgar Square in the heart of London.
A senior Scotland Yard official was quoted in the Daily Telegraph as saying anarchist groups plan to "deliberately target" the royal wedding.
Security on that day will be a nightmare. There are potential threats from al-Qaeda, Libyan dictator Muammar Qaddafi and now, anarchists.
London security expert Geoffrey Davis told INSIDE EDITION, "Anarchist groups are out there to disrupt because they are anti-royal, anti-establishment and that is also a very dangerous threat."
The same groups targeted Prince Charles and his wife Camilla last year, attacking the royal limo, which is the same vehicle Kate Middleton will use on her wedding day.
Ignoring the chaos in London, William and his brother, Prince Harry, and about twenty buddies held a bachelor party over the weekend. It was a subdued affair in a sprawling country mansion outside London.