The wooden boat was sailing from Penang island on the west coast of Malaysia to Indonesia's Aceh province when it sank Tuesday night in the Malacca Strait, East Aceh district police chief Ridwan Usman told reporters.

'At least 20 people were rescued alive and five bodies have been found,' he said.

The boat was carrying 45 Indonesian workers and three crew when it was hit by bad weather and heavy seas and sank 32 kilometres from Sumatra's northeastern coast, he said.

Navy ships were involved in the search for survivors but strong winds and high waves were hampering the operation.

The vessel is the third to sink in Indonesian waters this week, as the annual monsoon pounds the island chain.

At least 230 people are believed to have died when a ferry sank in a storm in the Makassar Strait off Sulawesi island on Sunday, and one has been confirmed killed after a cargo ship went down off Sumatra on Tuesday. -- AFP