The Western Highway is closed between Dimboola and Nhill after Police and emergency services responded to reports of a collision between three trucks in Gerang Gerung this morning.

Traffic between these two towns is currently being diverted via Jeparit, with local residents and drivers warned to be aware of increased traffic on the Dimboola-Rainbow Road, Jeparit-Nhill Road and through Jeparit.

Investigators have been told the collision occurred on the Western Highway shortly after 1 am this morning.

One of the trucks rolled off the road and came to rest in paddocks nearby.

The driver of the truck, a 20-year-old Dandenong North man, has been airlifted to hospital with life-threatening injuries.

A second driver, a 64-year-old Wangaratta man, has been transported by road to hospital with non-life-threatening injuries.

The third driver, a 61-year-old Bayswater man, was taken to hospital for observations.

It is expected that the Western Highway will remain closed for some time while investigators remain on the scene.

The exact cause of the collision is yet to be established and the investigation remains ongoing.