Rail services through Fife and Tayside were disrupted on Friday after a train hit a cow on the line.
Services between Aberdeen and Edinburgh are affected in both directions following the incident between Leuchars and the Tay Bridge on Friday morning.
ScotRail said the incident had resulted in delays and alterations to trains in Fife and the north east, which are expected to last until lunchtime.
Customers with valid train tickets can travel on selected Stagecoach bus services.
— ScotRail (@ScotRail) October 18, 2019
A Scotrail spokesperson said: “We apologise to customers who’ve been delayed as a result of this incident and understand their frustration when these things happen.
“Anyone delayed by 30 minutes or more is entitled to compensation under our Delay Repay scheme.
“To claim, simply keep hold of your ticket and visit the Scotrail website.”