A train conductor was punched in the stomach after asking two passengers to produce a valid rail ticket.
The men, who were on board the train to Glasgow, assaulted the conductor before waving a £5 note in front of him and getting off at Falkirk Grahamston.
The man did not suffer any injuries.
British Transport Police officers are appealing for information about the incident, which happened between Polmont and Falkirk Grahamston on March 5, between 5:30pm and 6pm.
One of the suspects is described as being white, around 5ft 8in, of slim build, and aged between 25 and 28 years old.
He is said to have short blonde hair, was speaking with a Scottish accent and had been wearing a black hooded top with black jeans.
The second suspect is described as white, 5ft 8, of medium build, also aged between 25 and 28 years old, with short brown curly hair which was shaved at the sides, and he spoke with a Scottish accent.
He was wearing a black top with a pocket on the front and black jeans.