Rescue workers have helped around 238 people get out of the water off the coast of Paupa New Guinea after a ferry with 350 on board sank, media reports said on Thursday.

The MV Rabaul Queen ferry sank off the coast northeast of the island on Wednesday night. The Australian Maritime Safety Authority (AMSA) has conducted the rescue and search mission, according to a statement from the agency.

The agency said that it had deployed eight vessels on the scene, who said that earlier reports of good weather conditions were not accurate, adding that “there are currently strong north-westerly winds” and sea swells of around 16 feet.

“So that means small boats can’t go out to rescue them, only the big ships,” disaster coordinator Charlie Masange told the Australia Broadcasting Corporation, referring to the poor conditions.

The owner of the ferry, Rabaul Shipping, told the ABC that there were only 258 people on board, in contrast to earlier reports from Australian officials, but it has not provided documentation to prove it.

The lack of documentation has caused problems among search and rescue workers, as they do not know how many people still need rescuing, according to the broadcaster.

Local officials said that the ferry sank in 3,000-feet water; there is no sign of the wreckage, and no sign of how the ship sank, ABC reported.

Prime Minister Julia Gillard said on Wednesday that Australia is trying to ascertain if there were any Australian nationals on board the ship, calling the disaster a “major tragedy.”

“But given the likely very high loss of life here, I think when this news comes to the attention of Australians around the country they will be thinking about the people of PNG as they respond to this tragedy,” she added.