Forty-two passengers have been injured and two are missing after two boats carrying Thai and foreign tourists collided in the Gulf of Thailand on the way to a popular island beach party, police said.
The speedboats were ferrying tourists to Pha-ngan island for a "full moon" party, a monthly event that attracts thousands of young, mostly Western tourists.
Provincial police officer Adipong Tapee said of the 42 revellers injured, 39 were hospitalised and included four Britons, four Australians and four Singaporeans.
He said among the injured were Irish, Norwegian, Malaysian and Thai tourists.
The website of The Nation newspaper said the boats collided and overturned before midnight on Saturday, throwing passengers into rough seas just off the island.