UPDATE: ScotRail has said that "disruption caused by a fault with the radio system between the driver and the signaller has now ended".
"Services are no longer affected by this problem," the rail operator said.
SCOTRAIL has said services across the country are “subject to delays” due to a “national fault with the radio system”.
The train operator made the announcement on its Twitter/X page at around 7.45am on Friday morning.
It said: “Due to a national fault with the radio system between drivers and signallers, services are subject to delays.
“Please note that this does not affect the safety of train running as alternative methods are in place.
“Speak to staff or press help points for further information.”
In an updated statement published around 8.15am, ScotRail said: "Our colleagues at Network Rail are experiencing an industry-wide problem with communications systems.
"Thankfully ScotRail services are operating well, with some minor delays in places. Please check before you travel."
It is understood services in England could also be affected as National Rail said “trains across the network are having to start their journeys later because of this fault and some may also be subject to cancellations or alterations”.
Travellers are being advised to check before they travel.
