JAKARTA • At least 18 people, including four children, died after a motorboat sank in choppy waters off the Indonesian island of Java, a government official said yesterday.

The 10m wooden vessel, with 57 people on board, was hit by high waves off Sumenep in East Java province on Monday, said a spokesman for the search and rescue agency.

A fleet of rescue vessels, a plane and local fishing boats saved 39 passengers, the spokesman added.

East Java police spokesman Frans Barung Mangera said the boat was suspected to be overloaded.

"The boat was hit by a large wave, overturned and sank," he said, adding that the traditional vessel was found by fishermen shortly after it was swamped.

This is the latest maritime accident to hit the archipelago nation.

Indonesia, a vast archipelago of more than 17,000 islands, has a patchy transportation safety record, with frequent ferry accidents often caused by overcrowding.

Last year, an overcrowded ferry with more than 200 passengers sank in Lake Toba in Sumatra. Eighteen people survived and nearly 200 were thought to have drowned in one of the world's deepest volcanic lakes.

In 2009, more than 300 people were estimated to have drowned when a ferry sank between the islands of Sulawesi and Borneo.

REUTERS, AGENCE FRANCE-PRESSE