A balaclava-clad teenager fired an airgun at a bus travelling through Edinburgh at the weekend.

The number 21 bus was on Hailesland Road in Wester Hailes, on Saturday night when it was struck by a pellet.

Passengers on the bus spotted a group of four people on a bridge over the Union Canal at around 8.30pm.

One of them was wearing a black balaclava and holding a blue gun.

The driver then heard a noise like a pellet hitting the roof of the bus.

Officers are keen to trace the boy who was wearing the black balaclava, who is believed to be 14 to 16-years-old, with a slim build and around 5ft 7in.

Constable Graham Whitelaw said: "Police Scotland takes airgun 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."

The incident came amid a Police Scotland clampdown on air weapons.

New legislation requiring all airgun owners to obtain a licence will come into the force at the end of 2016.

Anyone with information about the incident is asked to contact officers on 101.