Two males have been hospitalised after a school bus rolled over on the side of South Gippsland Freeway, Hallam.
Police say the bus left the freeway and rolled about 10.30am.
The 55-year-old driver from Carrum and his male passenger suffered non-life-threatening injuries, police say.
Both were taken by road ambulance to Dandenong Hospital.
Greater Dandenong Highway Patrol officers are investigating the rollover. The exact cause is yet to be determined, police say.
Any information or dashcam footage to Crime Stoppers on 1800 333 000 or crimestoppersvic.com.au