Constable Andy Denny, of Balclutha, said police were called to two incidents involving fireworks over a three-hour period on Saturday night.
Shortly before 11pm, police gave a 22-year-old Balclutha man a pre-charge warning after he threw lit fireworks from a moving vehicle in Frances St.
Three hours later, about 2am, four youths walked to the front of a Clyde St house, with one placing a 107-shot firework in the letterbox, and lighting it before running north along Clyde St.
The firework damaged the letterbox and woke the elderly occupants of the property, Const Denny said.
''This was a cowardly attack on a couple who are in their late 60s and early 70s and who are repeatedly targeted by local youths without provocation.''
The youth who placed the firework in the letterbox was wearing a light coloured ''Element'' branded hooded sweatshirt. Anyone who saw the incident or can identify the four youths is asked to contact Balclutha police.
''The combination of alcohol consumption and fireworks are a dangerous combination and further continued acts of stupidity will result in court action.''
Shortly before 3am youths set alight twigs, rubbish and debris they had collected at the car park near the Balclutha skateboard park in Lanark St.
Police discovered the fire and extinguished it.
Const Denny said there were strong leads on the identity of the offenders.
