Maritime officials say 85 people were injured, some seriously, when a ferry travelling from Hong Kong to Macau hit an unidentified object.
Hong Kong's marine department said the high-speed hydrofoil, carrying 105 passengers and 10 crew, crashed at around 1:20 am ((1720 UTC)) on a tourist route near an outlying island.
The vessel managed to sail back to Hong Kong after the accident.
The accident is sure to stir public concern about safety of maritime transport in Hong Kong's harbor, one of the busiest in the world.