A typical Changing of the Guard ceremony outside Buckingham Palace yesterday morning was briefly interrupted by a man waving around two large knifes and ranting unintelligibly.

Police say 54-year-old Talhat Rehman of North West London was standing among ceremony onlookers when he suddenly burst forward and began gesturing towards his own neck and chest with a pair of knives.

"He was shouting but it was quite unintelligible. Police were clearly telling him to drop the knife and instructing public to get back," said eyewitness Josh Greenberg.

An officer eventually managed to seize a moment of distraction, and fired a Taser barb into Rehman's back, sending him to the ground. He was quickly subdued, and the drama concluded without incident.

"He was not making threats to members of the public but he was challenged by police. He acted aggressively and a Taser was discharged," a Scotland Yard spokesman said in a statement. Rehman was charged with two counts of possessing a bladed weapon in public, and one count of affray.

In 2002, Rehman ran unsuccessfully as a Conservative candidate for a council seat in the London Borough of Brent, according to his son.

[video via Grant Shepherd]