From Brisbane to San Francisco, riders of the world's subways were on Sunday stripping down to their underwear for the 17th edition of what has become a global event: the No Pants Subway Ride.

As the name suggests, the occasion sees subway riders hitting train carriages specifically without wearing any pants.

“There is no agenda for the event apart from a desire to make others laugh and smile,” organizers Improv Everywhere said on its website.

The first No Pants Subway Ride took place in New York in 2002 with only seven participants, but the trend apparently caught on.

Independently organized No Pants events were expected to take place in over 60 cities on Sunday, according to Improv Everywhere, the creators of the original New York edition.

Epa photographers took to trains and stations in several European cities, including Prague in the Czech Republic and the German cities of Berlin and Munich, where they witnessed some of the scenes playing out among the bare-legged travelers.