Palace Guard's rude gesture makes YouTube

The Foot Guard, clad in the famous bearskin and scarlet tunic, was caught making the obscene hand movement by an American tourist.

She posted the clip on the YouTube website with the title "Buckingham Palace Plonker", prompting the Army to launch an inquiry.

"We're identifying the individual. This behaviour is unacceptable," an Army spokesman said.

The Foot Guards have become an iconic symbol of Britain and the Royal Family, and the daily the changing of the guard ceremony is one of London's biggest tourist draws.

Visitors regularly try to in vain provoke the stone-faced guards into a smile or a conversation, making this soldier's behaviour even more astonishing.