A blaze which broke out within a cell at a Scots prison last night, was "started deliberately, using paper" it has been revealed.
A young inmate was taken to hospital after being treated by paramedics for smoke inhalation after the alarm was raised at HMYOI Polmont.
Emergency services raced to site at around 8:04pm, with four fire engines spotted parked up outside at one point.

A senior prison source has since revealed the blaze was "deliberate and started with paper".
A spokesperson for the Scottish Ambulance Service confirmed one person was transported to hospital.
They said: “We received a call at 20:12 on Wednesday 7th April to attend an incident at HMYOI Polmont. We dispatched one ambulance to the scene and transported one patient to hospital.”
A spokesperson for the Scottish Prison Service said: "A small cell fired occurred at HMPYOI Polmont which was extinguished by staff.
"No staff or prisoners were injured, one Young Person received treatment for smoke inhalation."
In a statement a Scottish Fire and Rescue Service spokesperson said: "Operations Control mobilised four appliances to the scene, but the small fire had been extinguished prior to arrival.
"There were no reported casualties."