At least 10 people including a two-year-old child have been found dead, while 22 other people – including a German man and woman – were rescued and taken to hospital, he said.

Navy personnel have been dispatched to search for the remaining passengers, said Octavianto.

However, passenger manifests in the region often do not record all of those on board.

“For the time being the number of people on board is still an initial estimation. There could be people who are not on the manifest. We are waiting for people who may be reported missing by family members,” a search and rescue official said.

The accident occurred as the boat left Tarakan for to Tanjung Selor in North Borneo on Tuesday morning.

“Witnesses said the sea was quiet when the boat capsized so I don’t think the accident was due to rough seas,” said Octavianto.

“However the port was very busy and the boat traffic was quite high at that time, which may have triggered the waves.”

It is the latest fatal boat accident in the vast Indonesian archipelago, which relies heavily on boats to ferry people around its 17,000 islands, but has a patchy safety record.

On Saturday, a wooden boat carrying 18 people capsized in Papua province. Ten people died and three are missing in that accident.

At least 23 people died when a tourist boat from Jakarta carrying about 250 holidaymakers to celebrate the new year on nearby Tidung island burst into flames.

In November, more than half of the 101 passengers aboard a boat died after it hit a reef and sank off the Indonesian island of Batam, south of Singapore.

Additional reporting by Associated Press, Reuters