On a sunny Saturday in London a large group of people gathered in Trafalgar Square. At first, it is hard to tell what these group of men and woman are up to as they stand around eyeballing each other.
Are they there to protest, cause a riot or something else? Police officers watch nervously from the sidelines of the historic square as the crowd surges together.
It becomes clearer what is really going on when you can see what many people in the group are carrying in their arms; white pillows.
You see, for the sixth year running thousands of people came to the famous London square armed with a fluffy pillow ready to to battle it out for the International Pillow Fight Day.
Men and woman let their inhibitions go and attack each other with sheer delight. Pillows burst and feathers start to fly.
London was just one of over 100 cities around the world who took part in the event. Organized by the Urban Playground Movement, the event is seen as a way to get people outside and having fun.