Two people have died and at least 10 Australian tourists have been seriously injured in a bus crash in Port Vila, Vanuatu, with some being airlifted back to Australia on Tuesday for emergency treatment. 
The Australians, who had been travelling on Brisbane-based cruise ship Pacific Dawn, had been doing a tour near Port Vila when their bus crashed with another bus. 
The two people who died in the crash were Port Vila locals. 
P&O Cruises, which owns the Pacific Dawn, has confirmed that at least 10 passengers were seriously injured.
A spokesman said it was arranging for air ambulances from Australia and New Caledonia to airlift passengers to Brisbane or Noumea for specialist medical treatment.
An Australian air ambulance jet, with a critical care doctor and two nurses on board, left Brisbane at 7am on Tuesday for Vanuatu's capital, Port Vila.
An RACQ CareFlight Rescue spokeswoman said the organisation's Learjet 45 was expected to return to Australia later on Tuesday with two patients, who were likely critically injured. Another rescue flight is expected to leave for Vanuatu later on Tuesday. 
Three of the injured guests were transferred by air ambulance to Noumea on Monday night.
The P&O spokesman said most of the injured were likely to be Australian, given the Pacific Dawn was based in Brisbane.
"The injuries are significant - the sort of injuries you'd expect in road trauma," he said.
"We've made the decision to airlift them to take the pressure off health services in Port Vila."
He could not provide ages or genders of the injured, nor confirm if any children were involved.
An Australian woman told AAP that P&O has kept her family in the dark about the injuries her elderly grandparents suffered in a fatal bus crash in Vanuatu.
Sarah Amy said her grandparents, Moyna Exley and Brian Exley, both aged in their 70s, have serious injuries including broken bones and open wounds.
"We had no contact with anyone and only were able to get the information from the Aussie consulate. My family are slowly coping but we are all in distress," she told AAP.
Another many said his in-laws had been on board, and had suffered broken bones.
Danny Bushel said his mother-in-law had a compound fracture to her femur, and father-in-law has a broken left arm. 
Another woman said her grandmother in law had been injured: "I just want to thank p&o for the updates and the care they, and the local people, are providing to all affected. My thoughts are with the families of the deceased," she wrote. 
P&O passengers who had done similar tours in the past said they'd feared for their own safety while in Vanuatu.
"I went on one of the tour buses through P&O and it was the scariest I had ever been on - we nearly had a head on collision and the driver was speeding like a maniac, time P&O took responsability (sic) to sign up safe tour buses with experienced drivers with safty (sic) in mind. This was in Vanuatu in Port Villa," Val Mer wrote.
Another, Daniel Adams, agreed: "They need do drive safer and when we were there the van we were put into (after paying top dollar for the tour) had extremely bald tyres and then he was speeding on gravel roads. P&o need to monitor this better. My wife and I were scared!"
Photos published by the Vanuatu Daily Post showed ambulances and emergency workers rushing injured passengers to hospital.
It is believed that medical staff from the cruise ship have been sent to the local hospital to assist in treating the injured.
Images also showed the front of what appeared to be a mini-bus and another vehicle, both of which had been badly damaged in the incident.
The newspaper originally reported that 15 people had been seriously injured in a road accident. The tourists had been returning from a tour to the Ekasup Cultural Village.
But the Facebook page of the Vanuatu Daily Post received more than 100 comments from worried locals, concerned that their family or friends may have been among the injured.
P&O Cruises confirmed there had been an accident involving a tour bus carrying some passengers from the trip.
"We can confirm that there was a road accident in Port Vila this afternoon involving a tour bus run by a third-party local operator," it said in a statement.
"Initial reports are that 13 guests from Pacific Dawn were among those injured. A doctor from Pacific Dawn attended the scene to provide medical care and to support local emergency services," the statement to Cruise Passenger said.
Passengers were been treated in the ship's medical centre or at a local hospital and medical centre.
"The Australian Department of Foreign Affairs and Trade was alerted and we are receiving full consular support in Port Vila. P&O's Care team in Australia has been activated and the families of passengers injured in the accident have already been contacted or are in the process of being contacted. Our current priority in Vila is to ensure our passengers are receiving all possible care. Further updates will be provided," it said in its statement.
With Jorge Branco and AAP