Passengers were evacuated from a carriage after a Virgin Trains East Coast train caught fire in Fife.
The incident happened shortly before the Leeds-Aberdeen service reached Leuchars around 11:30am yesterday.
It caused significant disruption, with ten other trains cancelled for all or part of their journey.
A further 33 services were delayed for a total of nearly 15 hours.
An industry source said: "There was smoke coming from an engine.
"The fire brigade was called and customers were moved to safety.
"Some passengers were moved to another carriage in case of smoke.
"Then, when they got into Leuchars, the train was terminated and some passengers got onto Virgin Trains coaches. Others got ScotRail services onwards."
Another source said: "I understand the rear power car caught fire.
"The main alternator went up, I am advised."
"The train was later towed by another locomotive back to the Craigentinny depot in Edinburgh."
A spokeswoman for the Scottish Fire and Rescue Service said: "We were called at 11:39am to reports of fire in a compartment of a train at Leuchars train station.
"Three fire appliances were mobilised to the scene.
"Crews arrived to discover the fire had already been extinguished with no casualties reported.
"They ensured the area was made safe before leaving the scene at 1pm."
A spokesman for Virgin Trains on the east coast route said: “One of our trains was stopped at Fife due to an overheated alternator in the engine, which was automatically switched off by the safety system.
"The fire brigade was called and customers were evacuated as a precaution, though we can confirm that there no risk to those on-board.
"We’re sorry for the inconvenience this might have caused to customers, who can submit a claim for delay repay if their journey was delayed by more than 30 minutes.”