A video has been released which shows the moment a member of the Queen's Guard lost his temper and aimed his gun at a tourist who had been taunting him.
The 20-second clip, posted by YouTube user hngjms, shows a tourist mockingly imitate the Queen's Guard soldier as he is marching. He then proceeds to place his arm on the Queen's Guard's shoulder, causing the soldier to turn round and aim his SA80 rifle at the tourist, yelling: "Stand back from the Queen's Guard." The frightened tourist immediately runs away in response.
The video has now been viewed more than 16,000 times since being posted on 22 June.