British Transport Police are hunting a group of men who've been stopping trains by pulling the emergency cords in Hertfordshire and East London...
Officers are studying CCTV images of a group and say what they've been doing is "completely irresponsible and dangerous."
The incidents have happened on board Greater Anglian trains in the Cheshunt and Edmonton Green areas.
On each occasion, the train is forced to stop, which leads to lengthy delays as essential safety checks are made.
One of the incidents happened on the 8.32am Cambridge to Liverpool Street station on 5th November. The other incident occurred on board the 6.05pm Broxbourne to London Liverpool Street station on 16th November.
Inspector Steve Webster from British Transport Police, said: "The actions of this group are completely irresponsible and dangerous. They selfishly pull the emergency cord in order to stop the train, and then worryingly walk onto the tracks.
What they don't know is that other trains could be rushing towards them at high speed.
We're not sure why this group of men continue to pull these emergency cords. Whether they're doing it for a laugh or if they are trying to get back home a few minutes quicker.
Either way, it is vitally important we identify those responsible so that they know the dangers they are putting themselves in".
:: Anyone with any information can get in touch with BTP by sending a text to 61016 or by calling 0800 40 50 40 quoting reference 365 of 06/12.2017.
:: Alternatively, information can be passed anonymously to Crimestoppers on 0800 555 111.