Anti-capitalism protesters from the Occupy movement have begun a new protest in the City of London as part of a global day of action.
Other protests are underway in cities including Moscow, New York, Athens and Madrid.
Several hundred people have gathered outside St Paul's Cathedral for a rally, before moving on to demonstrate outside the offices of some of the largest firms in the financial heart of London.
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The plaque at number 16 Cowley Street in Westminster marks the brown brick Georgian townhouse where Sir John lived for 31 years.
A man reportedly armed with several knives has been arrested in Whitehall on suspicion of planning a terror attack, police have said.
Metropolitan Police officer, Tom Harrison, has been crawling the course since the race began on Sunday morning.