A Taiwanese-registered gravel ship with 15 crew members on board sank off the island on Monday, leaving six people dead and two others missing, officials said.
Taiwan's coast guard rescued seven people after the 2,998-tonne Hai Hsiang No 8 sank off Keelung port in the north of the island.
The coast guard said it had recovered six bodies -- four Indonesians and two Taiwanese -- and was searching for the captain and the crew manager, both from Taiwan.
"I was asleep when suddenly the captain ordered everyone to put on life jackets," a Taiwanese sailor said in an interview with the Cti news channel.
The accident happened early in the morning as the ship was on its way to Hualien harbour in the east of Taiwan packed with a full load of soil, the coastguard said.
The cause of the accident was not immediately clear, but local media reported that the vessel may have been overloaded.