Officers from British Transport Police are investigating threats made at knife point and are appealing for witnesses to come forward.
At around 1pm on Sunday 10 November, a member of train staff approached a man on a train from Edinburgh Waverley to Aberdeen.
The man swore at the conductor before producing a knife and threatening to use it.
The man is described as white, about 5ft11 in his mid to late 20s with black hair and was wearing a navy-blue tracksuit.
Anyone who witnessed the incident is asked to contact BTP by texting 61016 or by calling 0800 40 50 40, quoting reference 322 of 10 November.
Alternatively, you can contact Crimestoppers anonymously on 0800 555 111.
John graduated from Telford College in 2010 with an HNC in Practical Journalism and since then he worked for the North Edinburgh News, The Southern Reporter, the Irish News Review and The Edinburgh Reporter. In addition he has been published in the Edinburgh Evening News and the Hibernian FC Programme.