A speedboat carrying 27 Chinese tourists and several Thai crews exploded on southern Thailand's Andaman Sea near Phi-Phi Islands on Sunday.
A Thai was killed and 16 others have been found injured, according to local media.
The speedboat was on its way to Phi-Phi Islands and caught fire near the Viking Cave in the sea at about 1 p.m. local time (0600 GMT) on Sunday. Five Chinese were seriously injured, according to the Consulate-General of China in Songkhla.
The consulate said all the Chinese tourists have been helped ashore while the rescue team is still searching for the others. All the injured were hospitalized.
Local media said there was a fuel leak. The captain went to check the engine and it suddenly exploded. The fire quickly spread, prompting all the passengers to scramble for swimming vests and jump into the sea.
Local media said there were five Thai passengers and 27 Chinese tourists, including three children on board. A seriously injured Thai crew was later pronounced dead from burns.
The explosion is under investigation.