GREAT OCEAN ROAD: One tourist dead after bus plunges

One woman is dead and two people critically injured after a bus carrying six tourists plunged off a cliff on the Great Ocean Road.

Police said they believe the bus left the road and travelled 20 metres down a ravine near the intersection of The Boulevard at Gellibrand Lower around 2pm on Thursday.

The bus was believed to be carrying six adult tourists.

Emergency services are currently working to free four trapped passengers from the wreckage, an Ambulance Victoria spokeswoman said.

Three helicopters are at the scene to transfer the injured passengers to either the Royal Melbourne Hospital or The Alfred hospital.

Another four other ambulances are on their way to the scene.

VicRoads said the Great Ocean Road road is closed between Princetown Rd and Gellibrand River Road.

Drivers should detour via Princetown Road and Lavers Hill-Colac Road. Detour points are manned. 

Vicroads said drivers are advised to comply with any instructions given on site by emergency services or VicRoads.