- Metropolitan Police confirm taser was used in central London at 11:50am
- Photos show man holding knife to his throat during Changing of the Guard
- Queen and Prince Philip were at Sandringham Estate in Norfolk at the time
- Man arrested on suspicion of affray and has been taken to a police station
The middle-aged man walked through crowds of tourists clutching two large kitchen knives before police surrounded him and used a Taser stun gun to disarm him.
As a policeman shouted a warning call of 'Taser, Taser, Taser' to his colleagues, the knifeman lunged forward, brandishing a six-inch blade in a series of swipes, before falling to the floor as he was stunned by the electrical charge.

Dramatic: Police officers tasered a man holding a knife to his throat outside Buckingham Palace yesterday

Scary: The dramatic incident saw the man brandish two knives in front of hundreds of terrified tourists

Down: The man charged towards a police officer outside Buckingham Palace who fired a taser gun at him
Police officers shouted to tourists to keep away from the man as they raced to surround him.
The man, who clutched a set of wooden beads and wore a flat woollen hat similar to the pakuls traditionally worn by men in parts of Pakistan and Afghanistan, was later arrested.