London: Over 400 people joined an annual event in the British capital city, on Sunday, to mark the "No Pants Subway Ride" day.

The bizarre ritual began as a small prank in New York almost 16 years ago, and has now spread to more than 60 cities across the world. The event calls on the participants to brave the cold weather barelegged. People of all ages got involved in the event, in which they were wrapped up for winter on top and bare below. Despite a bitter cold that could bring subzero temperatures overnight, travellers embraced the gimmick, where they were encouraged to keep a straight face and "sit in the train as they normally would".

Images shared on social media showed participants sporting brightly coloured underwear with their exposed legs as they sat casually on the train. The event's founders said the bizarre tradition was launched to simply make people laugh on their journey.