A young passenger was injured when thugs launched a hail of missiles at a bus as it drove through Dundee on Sunday.
Windows were smashed during the attack, which Police Scotland said could have had “catastrophic” consequences for all on the bus.
A 16-year-old boy suffered a leg injury as a result of the stone-throwing, sparking a major investigation by local officers.
They are seeking five males, aged between 11 and 20, who are believed to have been responsible for the attack.
They are said to have been wearing dark clothing and were seen near Lothian Crescent at around 6.25pm, when the bus was targeted.
Police Scotland said: “The implications of throwing any type of missile at a moving vehicle can be very serious indeed, not least when it is public transport carrying passengers.
“The implications of this attack for anyone within the vehicle, or anyone nearby for that matter, could have been catastrophic.
“On this occasion a young man received a minor leg injury, but the consequences could have been far, far worse.
“Those who get involved in this reckless behaviour may view it as a bit of harmless fun, but they should consider the potential consequences of their actions.
“They have the potential to threaten lives.”
Officers are keen to trace anyone who may have witnessed the incident or seen the group of young men on Sunday evening.
The bus was travelling on Lothian Crescent, near to the junction with Haddington Avenue, in the city’s Whitfield area.
Anyone with information should call Police Scotland on 101 or Crimstoppers anonymously on 0800 555 111.