Several letterboxes on the Sunshine Coast have been filled with cheaply-made explosives, causing major damage and prompting a police that residents are at risk of injury.
With dozens of letterboxes being destroyed across the region, officers said they believe young people are responsible for the destruction, with the explosions commencing at the start of the school holidays.
Inspector Mark Cordwell said the letterbox bombings pose a risk not just to residents and neighbours, but also to those making the explosive, as well as causing major damage to property.