Commuters have been warned to expect delays to rail services from Inverness and Aberdeen to Glasgow and Edinburgh.
Trains face signficcant delays due to a signal fault.
Scotrail have advised customers that tickets are accepted on alternative transport that include Stagecoach buses, First buses and Edinburgh Trams.
Due to a fault with the signalling system between Croy and Larbert, the line is blocked
As a result of the delays train services between Glasgow Queen Street and Aberdeen could be cancelled or delayed.