Parents and children have been warned to remember the dangers of straying onto railway tracks after two separate incidents.
The British transport Police are investigating how debris was placed on the Leeds to Nottingham railway line on successive Mondays earlier this month.
In both cases, a number of drivers spotted ‘very young’ children near the line.
Sgt Mark Rushin said: “The railway is a dangerous place for trespassers. I want youngsters to understand the seriousness of trespassing on railway tracks and parents or responsible adults to emphasise the dangers to them.”
Anyone with information on the Cotmanhay incidents is asked to contact British Transport Police on 0800 405040. Information can also be passed anonymously to independent charity Crimestoppers on 0800 555111.