A man threatened to stab a train guard after a row erupted over his ticket.
British Transport Police are appealing for witnesses to the threat on a service travelling between Flint and Shotton .
CCTV images have now been released of a man they wish to speak to in connection with the incident.
A spokesman said: "The incident happened at around 2.50pm on Monday, February 11.
"The suspect is reported to have boarded the train at Rhyl .
"He then began acting aggressively towards the guard after an issue with his ticket."
Police added: "The man then began verbally abusing the victim before threatening to stab him if he ever saw him again.
"The suspect then left the train at Shotton ."
No knife was seen during the incident, police said.
Anyone who knows the man pictured in the CCTV images, or who witnessed the incident, is asked to contact British Transport Police on 61016 or by calling 0800 40 50 40 and quoting reference 317 of 11/02/19.
Alternatively, call Crimestoppers anonymously on 0800 555 111.
