A British woman has died and a British man is feared missing after a speedboat capsized near Koh Samui, Thailand.
Another British national was injured in the accident, the Foreign Office said.
Thai tourist police said 32 passengers and four crew were on board the Ang Thong Explorer, which was travelling from Mo Ko Ang Thong National Park when it hit a "big wave" and capsized at 5pm local time.
A second woman from Hong Kong also died, while a British man and German woman are missing, police added. Police named the missing Briton as Jason Robert Parnell who was in Thailand with his wife Puga Parnell. She is said to have been unhurt.
Several people were rescued by another speed boat while the rest were picked up later by an official rescue boat, the Bangkok Post reported.
Two bodies were recovered from the sea. A senior police spokesman told the Press Association: "We're still trying to check everyone. One British woman has died and one from Hong Kong. Two people are missing."
He added that the bodies of the two women had been recovered from the sea.
According to a port official, the boat capsized because of strong winds and high waves. Some of those on the vessel were thrown overboard and became trapped beneath it.
At least one person had to be pulled from the hull after rescuers used a hammer to smash through it.
The boat's captain, Sanan Seekakiaw, said he had asked all tourists to wear a life vest but that some had taken them off during the journey.
A spokeswoman for the Foreign Office said: "We are supporting the family of a British woman who has sadly died following a boat accident near Koh Samui, Thailand.
"Another British national has received treatment in hospital for injuries suffered in the same incident. We remain in contact with local authorities in Thailand for further information."
It is believed there were other British people on board the boat but they are understood to have been released from hospital following treatment for any injuries.
Four people remained in hospital on Friday, one with a broken shoulder and another with a skull fracture. The other two suffered from lack of oxygen and were being monitored for lung infections.
Koh Samui is among the most popular Thai island destinations for backpackers and luxury holidaymakers alike, and is known for its beautiful beaches, coconut plantations and waterfalls.
Additional reporting by Press Association
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