At least eight people drowned when an overloaded boat sank in central Indonesia Thursday during a traditional ceremony marking the end of the Eid al-Fitr holiday, an official said.

Thirty-four people were plucked to safety when the wooden boat went down in the afternoon as it travelled from Panjang island to a beach in Central Java province, local search and rescue official Agung Hari Prabowo told AFP.

"Eight people, including two children aged 5 and 7, died in the accident," he said, adding that those saved by rescuers and fishermen had only minor injuries.

"It was clearly overloaded -- the boat could only carry 20 to 25 people."

Prabowo said he was unsure whether other people might still be missing and rescue teams would continue searching on Friday.

The travellers were performing a ceremony to mark the Muslim Eid holiday, which comes at the end of the holy fasting month of Ramadan.

It involved putting an offering of a buffalo head into the sea to ask for good fortune and express thanks to God.

The Eid holiday fell last week in Indonesia, which has the world's biggest Muslim population, but many people are still off work and celebrating.

Indonesia's 240 million people are spread across 17,000 islands and are heavily dependent on a network of boats for transport, but the country has a poor maritime safety record.