Emergency services have launched a major response after a ScotRail passenger train derailed near Stonehaven in Aberdeenshire early this morning.
There are reports of around 30 emergency vehicles - including air ambulance support - at the scene, with more continuing to arrive.
British Transport Police were called to the scene around 9.43 this morning, after a night of torrential rain and thunderstorms in Scotland have caused flooding and travel disruption across central and eastern areas.
The initial theory is that a landslip could have caused the train to derail. The train had two locomotives and four passenger carriages. One of the front locomotives and three passenger carriages have reportedly been derailed and fallen down a slope into a valley by the side of the tracks.
The police said paramedics and the fire brigade were also in attendance.
In a briefing statement to Holyrood, the first minister Nicola Sturgeon said: 'I have just come off a call with Network Rail and the emergency services and although details are still emerging I am afraid to say that there are early reports of serious injuries.
'The Scottish Government resilience room is operational and I will be convening a SGoR (Scottish Government Resilience) meeting this afternoon. Updates will be made as soon as they are available. However my immediate thoughts and I am sure the thoughts of everyone in this chamber are with those involved in this incident.
A ScotRail spokesperson added: 'We're assisting the emergency services with an incident near Stonehaven, and will provide more information when available.'
Paul Plummer, chief executive of the Rail Delivery Group which represents the rail industry said: 'We are saddened to learn about the incident in Aberdeenshire today and our thoughts are with those affected. While an investigation will follow, our current focus is to provide every support we can in the immediate response.'
Earlier today, Network Rail released tweeted statements and video that said there had been reports of a landslips in Scotland and flooding on the lines.