A conductor has been hit by a brick which was thrown at a moving train.
The worker was on the 23.56 East Kilbride to Glasgow Central train when a brick smashed through a window of the rear driver's cab and hit him on the head.
British Transport Police said the incident happened at around 12.20am on Monday between Pollokshaws West and Crossmyloof stations.
The conductor was treated by paramedics when the train arrived in Glasgow. He received a cut to his head but did not need to go to hospital.
BTP Detective Constable David Merchant said: "This reckless and stupid act could have had even more tragic circumstances.
"I am appealing for anyone who was in the vicinity of Pollokshaws Road, Durward Avenue or Shawmoss Road at the time of the incident and who may have seen anyone acting suspiciously to contact BTP as a matter of urgency."