Pranksters descend to No Trousers invasion of London Underground
Pranksters staged a cheeky invasion of London's underground network to take part in No Trousers On The Tube Day.
What began as a madcap idea by a handful of people on New York City's mass transit system in 2002 has grown into an international celebration of silliness.
Now there are around 9,000-10,000 people who take part each year in the global good-willed stunt.
Hundreds of Britons, of all shapes and sizes, stripped down and kept a straight face as they rode on the underground in their underwear.
Confused commuters also saw the pranksters take part in a mannequin challenge on the concourse at Kings's Cross Station in central London.
Organiser Ivan Markovic said: "We have been running it for eight years here.
"We travel the Tube on the first Sunday of the year and just make a scene. We make people smile. We make people laugh and we get some lovely reactions."
It was a bit of a bummer that the tail end of the stunt clashed with the 24-hour Tube strike because "unfortunately I think a lot of people will not be able to make the after-party - which sucks," Mr Markovic said.