Emergency services were called to reports of the single vehicle crash on Chapel Rd just before 5pm.
Nine people were in the minibus at the time of the incident, all from the Greater Shepparton area.
Four people were located deceased at the scene and have since been identified.
They are a 17-year-old male, a 34-year-old male, a 51-year-old woman and a 45-year-old female.
Paramedics treated five others at the scene, all remain in a serious condition in hospital.
They are an 18-year-old woman, a 16-year-old female, a 16-year-old female, a 16-year-old female and a 39-year-old man, who remains in hospital under police guard.
All those involved were working in the area and are from overseas.
The exact circumstances surrounding the crash are yet to be determined and investigations remain ongoing.
Anyone who witnessed the incident, has dashcam footage or any other information that could assist police is urged to contact Crime Stoppers on 1800 333 000 or submit a confidential report online at www.crimestoppersvic.com.au/