Rescuers and fishermen saved 30 injured people and were looking for more survivors.
Local police spokesman Lieutenant Colonel Okto Riwu says the fishing boat was designed to hold only 30 people but had more than 70 onboard. It sank shortly after a 2-meter wave crashed into it off Flores island.
The boat was participating in a parade at sea while taking the passengers to Larantuka town in East Nusatenggara province for Good Friday prayers and processions through the town.
Boats and ferries are popular transportation in the vast Indonesian archipelago, and accidents due to overcrowding and poor safety standards are common.
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