Rescuers have rescued more than 230 survivors from the sea off Papua New Guinea's east coast after a ferry sank with as many as 350 people on board, officials say.
An aircraft from Australia, three helicopters and eight ships scoured the area after the MV Rabaul Queen went down while traveling from Kimbe on the island of New Britain to the coastal city of Lae on the main island, early on Thursday, the Australian Maritime Safety Authority said.
The ferry sank 80km east of Lae, the South Pacific country's second-largest city, and 16km from shore, it said in a statement.
The Australian Broadcasting Corporation quoted police in Kimbe as saying that most of the passengers were students and trainee teachers.
An official at the scene said the ferry capsized in rough seas and sank four hours later, Papua New Guinea's Post-Courier newspaper reported.
Sam Maiha, the National Weather Service chief, said shipping agencies had been warned to keep ships moored this week because of strong winds, the newspaper said.
Peter O'Neill, the Papua New Guinea prime minister, said the cause of the accident was unknown, but acknowledged that safety in the shipping industry was lax.
"We need to bring some safety measures back into this industry," he said.
Unconfirmed number of missing
O'Neill said more than 300 people were aboard the ship, although the precise number had not been confirmed.
An Australian search and rescue airplane based in the northern city of Cairns reached the scene by afternoon and two other Australian airplanes were on their way.
Carly Lusk, spokeswoman for the Australian Maritime Safety Authority, said the crew of the first plane threw several life rafts to survivors in the water. She said 238 survivors had been recovered by late in the day.
She said 350 people were believed to be on board the ferry, but Papua New Guinea's National Maritime Safety Authority said the figure was likely lower.
"I cannot confirm or deny the 350 missing number. It is hearsay," said Captain Nurur Rahman, the authority's rescue coordinator.
"I have not seen the manifest as yet, but it is likely around 300."
PNG's National Maritime Safety Authority (NMSA) said the ship had capsized but it was awaiting more details from officials at the site.
"This is obviously a major tragedy - 350 people on board a ship that has gone down. It is likely a very high loss of life here," Julia Gillard, the Australian prime minister, said in Melbourne, before reports of the rescue of survivors emerged.
Martin Mosi, head of Papua New Guinea's National Disaster Centre, said it was very difficult to say what the cause may have been.
"Is it weather, is it overloading or is it something to do with the vessel itself? We do not know but that will certainly come to light very soon," he added.
Rabaul Shipping-owned Star Ships, one of Papua New Guinea's largest passenger ship operators, runs regular services to the nation's outlying islands including to New Britain's Kimbe, a popular dive site that attracts tourists from across the world.