A member of the Neighbourhood Police Team said the two youths had been seen on the roof of the middle bus shelter at around 19:30 on Tuesday 15 September.
One of them was wearing a dark-coloured hoodie or coat, dark trousers and light-coloured trainers.
The other was wearing a light-coloured t-shirt, black trousers and black trainers.
Anyone with information that can help police identify them have been asked to contact PC 204 Mark Shields on 725111 or contact Crimestoppers anonymously on 0800 555 111.