Tragedy struck again in Indonesian waters when a passenger ferry with 150 people aboard sank off Maluku island in the country's east killing eight people.

Dozens were rescued but 60 are still unaccounted for on Wednesday, when the ferry sank after being pounded by three-metre high waves off Southwest Maluku regency.

"It is likely that the boat sank due to overloading. It is almost Christmas; people want to celebrate it in their hometowns. That is why so many people boarded the boat," regency secretary Mathias Malaka said Wednesday, as quoted bykompas.com.

The ferry left Saumlaki port at 6 a.m. for Pulau Sera. It sank around 9 a.m.

There is no record of the boat and its number of passengers at the Southwest Maluku Port and departed without permission, Malaka said, according to The Jakarta Post.

Rescuers trying to retrieve bodies from the water are being hampered by heavy rains, strong winds and rough seas.

The sinking of the ferry came four days after a boat carrying about 250 asylum seekers from the Middle East capsized off the coast of East Java. So far, more than 40 survivors have been rescued with 40 bodies recovered.