This is the alarming moment a "reckless" thrill-seeker was filmed riding between the carriages of a moving DLR train.
The shocking footage, posted online by YouTube prankster Trikkstar, shows a youth climbing between two carriages of the train when it stops at Westferry Station, east London.
He is filmed from inside one of the carriages by an accomplice and waves at shocked passengers as the train moves towards Limehouse.
When it stops at the station, he is told to climb down by an official but returns to attempt the stunt for a second time that night.
The six-minute clip, which was uploaded on Thursday, shows the same teenager climbing onto the back of a DLR train travelling towards Woolwich Arsenal in the evening.
He clings onto the train for several stops and waves at stunned bystanders on the station platforms.
It is believed the footage was filmed on Saturday, February 25.
Transport for London branded the footage, some of which was filmed on a head-worn camera, as “extremely reckless”.
The transport body said it was working with the police to ensure the appropriate action was taken.
Steve Burton, TfL’s Director of Enforcement, said: “This behaviour is extremely reckless and will not be tolerated.
“The actions of this individual not only pose a risk to his personal safety, but also the safety of DLR passengers.
“We are working with British Transport Police to ensure appropriate action is taken.”
The Standard has contacted BTP for comment.
The force has previously issued a warning to so-called “train surfers” urging them to think of the consequences of their actions and that they are putting their lives and others in danger.
DLR trains travel at speeds of up to 50mph and operated using a driverless, computerised system.