Police have condemned "mindless" offenders who "trainsurfed" along a rail platform.
Officers from the British Transport Police (BTP) released CCTV images of the men hanging from the driver's door as it left the station at Accrington, Lancashire.
Police are looking for the men involved, saying that the railway "is not a playground".
Train surfing is a worldwide problem. In October 2010, a man rode on top of a subway car around New York, while Stockholm has also faced issues with daredevils.
Earlier this year a teenager in Australia who boasted on Facebook that he was the "Kelly Slater of train surfing" was killed after being electrocuted on the tracks.
In Indonesia recently authorities installed concrete balls above train carriages in an effort to deter people riding on top of carriages.
Perhaps most shocking of all, this video of train surfers in India went viral last year even after officials denounced it as a "dangerous and insane act of rashness which nobody should replicate".
Pc John Phillips said of the UK offenders: "It is hard to believe that anyone, let alone grown men, could be so mindless as to try to surf off the side of a train ... it would only take a minor slip for them to fall between the train and the platform.
"If the danger isn't a deterrent then I hope the threat of police action might be. Those who survive this type of incident can rest assured that BTP will do everything possible to trace them and put them before the courts.
"We simply will not tolerate any behaviour which puts lives at risk. The railway is not a playground and should not be treated as such."