Fireworks were used to blow up a letterbox near Portland on Saturday causing a loud bang that woke up the property owners at 1am.
Sergeant Sean Elliott, of Portland police, said the force of the blast blew pieces of the letterbox as far as 15 metres away.
It is believed commercial fireworks, or something similar, were used to blow up the steel letterbox at the rural property on Berrys Road at Gorae, Sergeant Elliott said.
“If it’s going to blow a letterbox that far, it’s going to do some serious damage if someone is standing next to it,” he said.
“There’s a reason fireworks were made illegal.”
It follows a similar incident in Portland about three weeks ago when a letterbox was blown up with a pipe bomb.
In that incident, the letterbox was obliterated and prompted Victoria Police bomb response unit members and an arson chemist to travel to Portland.