A train guard working on a service between Chester and Flint was threatened.
British Transport Police have released a picture of a man who they want to speak to in relation to the incident, which happened on January 23 at around 6.35pm.
British Transport Police issued an appeal for information on Facebook, saying: “Recognise this bloke?
"We want to talk to him after a train guard was threatened on a service between Chester and Flint. It happened at around 6.35pm on 23 January.
"Know him? Let us know on 0800 40 50 40 or text 61016, quoting reference 449 of 23 Jan.”