Police and emergency services are currently responding to an incident in Bayswater on the Mountain Highway at Elm Street, Victoria Police say.
It is believed a utility vehicle containing a number of Acetylene gas bottles travelling city bound has exploded about 8.20am resulting in damage to homes in the immediate vicinity.
Emergency services have isolated the scene however a large area has been cordoned off due to the incident.
Traffic diversions are in place from Stud Road on the Mountain Highway, with east and west-bound lanes blocked.
Police advise motorists to seek alternative routes as the area may be closed for an extended amount of time.
A man, believed to be in his 50s, has been transported to hospital in a life-threatening condition.
Worksafe are investigating the incident.
The exact circumstances surrounding the incident are yet to be determined and anyone with information is urged to contact Crime Stoppers.