Police Scotland are looking for witnesses after a youth fired an air gun at an LRT bus on Saturday 25 June 2016.
The incident happened around 8.30pm on Hailesland Road when the number 21 bus was travelling towards Clovenstone.
The driver saw a group of four youths standing near to a bridge over the union canal. One of them was wearing a black balaclava covering his face and holding a blue-coloured gun.
The driver then heard a noise like a pellet hitting the roof of the bus.
Officers are now appealing for information that can help them to trace the individual responsible.
They are particularly keen to speak to the youth wearing the black balaclava, aged around 14 to 16 years old, of slim build and around 5 ft 7 inches tall or anyone who saw him.
They are also keen to speak to anyone who saw the group of youths aged between 14 and 16 who were in the Hailesland Road area on Saturday around 8.30pm.
Police Constable Graham Whitelaw of Wester Hailes police station said:
Police Scotland takes air gun crime extremely seriously and we are keen to trace this individual.
This was reckless behaviour that caused the bus driver fear and alarm when he was simply doing his job.
Anyone with information is asked to contact officers on 101.