Rescuers plucked more than 230 survivors from the sea after a ferry sank yesterday with up to 350 people on board.
An aeroplane from Australia, three helicopters and eight ships scoured the area after the MV Rabaul Queen went down while sailing from Kimbe on the east coast island of New Britain to Lae on the mainland.
Police in Kimbe said 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.
Peter O'Neill, the Prime Minister of Papua New Guinea, said the cause of the accident was unknown, but admitted safety in the shipping industry was lax. "We need to bring some safety measures back into this industry," Mr O'Neill added.