Fifteen dead and several missing as boat sinks off Indonesia's Sulawesi island

A rescue team prepares to join the search for survivors off Sulawesi island in Indonesia after a boat sank. AFP

A ferry sank off the coast of Indonesia's Sulawesi island early on Monday morning, killing 15 people.

Thirty three passengers on board were rescued or swam to safety after the accident, local emergency services said. Two of those rescued were in hospital, they added.

The boat sank after midnight local time, Indonesia’s search and rescue agency said. An investigation is under way.

Marine accidents occur frequently in the South-East Asian archipelago nation of about 17,000 islands, where people rely on ferries and small boats to travel, despite poor safety standards.

The boat was crossing a bay between the villages of Lanto and Lagili in Central Buton regency on Muna Island, said local rescue office spokesman Wahyudin, who like many Indonesians goes by one name.

A search team will dive around the accident site, while another will search the water’s surface using boats, he said.

The search and rescue agency shared images of rescuers, the search effort and several dead bodies covered by sarongs laid on tarpaulin at a local hospital.

It is common in Indonesia for the number of passengers on a boat to differ from the manifest.

Passengers had previously been recorded as missing because they had "rescued themselves, and once they got on land, they went home", Wahyudin said.

The vessel was a wooden passenger boat and not a ferry as initially reported, according to Wahyudin.

He refused to confirm local media reports that the boat was overcrowded.

Indonesian media reported that villagers had travelled for a local celebration and gathered on an overcrowded boat that capsized on its way back across the bay.

In 2018, more than 150 people were killed when a ferry sank in one of the world’s deepest lakes on Sumatra.

In May last year, a ferry carrying more than 800 people ran aground in shallow waters off East Nusa Tenggara province and remained stuck for two days before being dislodged.

No one was hurt in that accident.