Waverley Station has been evacuated after the fire alarm was activated.
Fire crews arrived at the station around 10.50am this morning after smoke was seen coming from a vent.
ScotRail says services have been disrupted.
National Rail said: “The fire alarm was sounding at Edinburgh and the station had to be evacuated. The emergency services have attended the incident and allowed the station to reopen. Trains will continue to be delayed, revised or cancelled whilst the service is restored.
“We anticipate a good service will be operating by approximately 1pm.
“We’ve been advised by Network Rail the incident was not security or crime related.”