A teenage girl has been airlifted to hospital after a school bus collided with a truck north-west of Melbourne.
The crash took place on the Western Highway at Bacchus Marsh at about 3.15am.
The bus, with students on board, rolled down an embankment.
One girl suffered serious injuries, as did the male truck driver.
The other 26 students on the bus, along with four adults and the bus driver, will be taken to hospital for observation.
The Melbourne-bound lanes of the Western Highway are expected to remain closed for several hours and motorists are urged to take an alternative route.
Any concerned parents seeking information regarding their children are asked not to attend the scene and to instead call Ballarat Police Station on (03) 5336 6000.
Police are investigating.
