JAKARTA (AFP) - Seven people died, including three children, when a boat carrying dozens of Christian worshippers celebrating Easter sank on Friday off eastern Indonesia, the police said.

The worshippers were holding a traditional sea ritual in waters off Flores Island when one of the wooden boats sank before noon, district police chief Dewa Putu Gede Artha said.

Fifty-three people were rescued in the incident which happened off the coast from Larantuka town, in the East Flores district of East Nusa Tenggara province.

"We found seven bodies, including three children," Mr Gede Artha told AFP, adding that the boat was on its way to join other vessels for the Easter celebration.

The exact number onboard is not known, and rescuers were still searching for possible survivors, the police chief said, with officials gathering information from relatives about those who may be missing.

District disaster management agency chief Paulus Igo Geroda said that four people remained missing, based on relatives' accounts, and that the other 30 to 40 boats that joined the ritual have returned safely.

The Indonesian archipelago of more than 17,000 islands has a poor sea safety record, and fatal accidents are common.