Police and rescue agency officials said by Friday morning a further 20 bodies had been recovered from the sea off the Indonesian island of Batam.

There were 101 people on the speedboat carrying migrant workers and their families that capsized in stormy weather early Wednesday morning, and 39 of the passengers were rescued. Two of its three crew also survived and were later arrested. Twenty-two people are still missing.

"This search is not easy," said Abdul Hamid, head of the local search and rescue agency. "Strong winds and currents were hampering our efforts and the sea was murky, making it difficult for rescuers to look below the surface."

The boat was carrying Indonesian workers home from Malaysia. Police suspect the trip was illegal and the workers were undocumented because of the high fares that passengers said they paid.

The boat was about 7.5 kilometres (4.5 miles) from land when it sank.

Speedboats and ferries are a common form of transport in Indonesia, a sprawling archipelago. Sinkings are common due to poorly enforced safety regulations.

One of the worst ferry sinkings in recent years occurred off Sulawesi island in 2009, killing more than 330 people.

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