UPDATED 1.35PM: Fifteen elderly tourists have gone to hospital after their bus plunged down a bank and ten metres into a creek in the central North Island.

It happened just after 8am this morning, at the intersection of State Highways 47 and 48 in Tongariro Forest Park.

A woman had to be cut out of the wrecked bus, which was partially submerged in water.

Rain and low cloud meant rescue helicopters couldn't reach the scene and had to wait five minutes drive away.

The passengers are all visiting from Britain and the United States.

They were on their way to Napier after staying at Chateau Tongariro Hotel.