Some 500 Londoners threw caution to the wind, along with their trousers, for this year’s international ‘No Pants Day’, riding half naked through the capital’s underground train service.

Oragniser of the event Ivan Markovic said “we’re, we’re not raising awareness for anything, it’s not a political statement, we’re just trying to make people smile, to bring something different to someone’s day.” Participants met in London’s Leicester Square before splitting up in to groups and taking various routes on the underground.

The event that now takes place in cities across the world every year originated in New York from improv group the Stiff Upper Lip Society.