ScotRail has issued a warning to travellers that there will be "cancelled, delayed or revised" train services in Glasgow on Wednesday.
The train operator took to Twitter to inform passengers of a "signalling issue between Perth and Gleneagles". This will affect services between Glasgow Queen Street and Dundee, Aberdeen, and Inverness until it is resolved.
Posting on Twitter, ScotRail wrote: "We’ve been advised by @NetworkRailSCOT of a signalling issue between Perth and Gleneagles. Staff are on site investigating and we’ll keep you updated.