A smoke bomb was set off at a busy train station after the St Mirren v Morton derby match over the weekend.

Officers are hunting a man after the smoke bomb was "recklessly discharged" on the platform of Paisley St James station.

The incident happened shortly after the St Mirren and Morton SPFL Championship match on Saturday April 16.

The man, aged around 18, discharged the pyrotechnic at around 5.15pm just as the 4.55pm service from Glasgow Central to Gourock arrived at the station.

He is described as having dark hair and wearing a grey hooded top with a red logo on it, jeans and trainers. He boarded the train and is believed to have got off at Greenock West station.

Detective constable Marc Francey, the officer in charge of the inquiry, said: "The platform was extremely busy with people waiting for the train and the dangers and potential circumstances of such a stupid action cannot be underestimated.

"If you were at the station and witnessed the incident please contact British Transport Police as a matter of urgency."

Information can be given to British Transport Police on 0800 405040 or by texting 61016.