Five people were injured, with four taken to hospital, when an escalator malfunctioned at a train station.
Emergency services were called to the scene at Argyle Street station in Glasgow shortly after 9am on Wednesday.
British Transport Police (BTP) said five people were treated for minor injuries and four of them were taken to hospital.
ScotRail said all escalators at the station have been turned off to allow them to be fully checked by Network Rail engineers, who are responsible for managing the escalators.
Trains did not call at Argyle Street between around 9.30am and 10.30am due to the incident.
Phil Campbell, ScotRail head of customer operations, said: “We are sorry to customers who have been affected by this incident, which was the result of an escalator malfunctioning.
“Our staff at the station were on hand to help those needing assistance, and we are now carrying out a full investigation to establish the cause.
“The safety of our customers and our staff is our priority, and the escalators will remain closed until they have been checked by engineers.”
BTP said the Office of Road and Rail has been notified about the incident.