Major Collision Investigation Unit detectives are heading to the scene of a collision that occurred between two motorbikes in Irymple this afternoon.
Investigators have been told two men riding dirt bikes were travelling toward one another on a dirt track beside the railway line when they collided with one another about 12.30pm.
Both male riders sustained life-threatening injuries and were airlifted to hospital.
The exact cause of the collision is yet to be determined and police are appealing to anyone who may have been on the bike track today between Redcliffes and Irymple to contact them.
Anyone who witnessed the collision or with footage of any bikes riding on the track is urged to contact Crime Stoppers on 1800 333 000 or submit a report online at www.crimestoppersvic.com.au.