A man shouting and holding knives has been tasered by police outside Buckingham Palace.
The drama unfolded as hundreds of tourists and Londoners gathered to watch the changing of the guard.
A warning - Nick Thatcher's report contains footage that some viewers may find upsetting.
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A man who fired at officers from the National Crime Agency has been convicted at the Old Bailey.
Want to know its posh name? It's a 'Track Retrieval Device'.
Unite said its members in the capital's 18 bus operators had supported walkouts by 85%, and action short of a strike by 9-1.