Train services between Perth and Dundee were disrupted by a signal fault on the line on Tuesday morning.
The issue was reported at around 7.30am and affected trains travelling between the two cities, such as those between Aberdeen and Glasgow.
The problem was resolved at around 9am but there has also been a knock on effect to other services on the line.
NEW: @NetworkRailSCOT have advised of a signal fault between Perth and Dundee. Engineers are on site and doing what they can to fix the problem. Services will be delayed or altered at this time. We'll update further, once we have more information from staff on the ground. ^Ste pic.twitter.com/egCNSPrRF9