Three tourists and a guide were injured while swimming near a speedboat that exploded in flames near Koh Mai Thon, off the coast of Phuket, on Tuesday morning.
Two crew members of the Thana Marine 555 were also injured, including the captain. All six were taken to hospital.
The boat had earlier left Tha Chalong pier, taking 33 tourists and a guide to Mai Thon island.
It developed engine trouble then caught fire and exploded about 9am, after arriving at the island.
When the fire started there were three people on board, the captain and two crew. Some tourists were swimming in the sea nearby.
The captain and one crew member suffered burns. Three tourists and the guide sustained shrapnel wounds from the explosion.
A fireboat and another speedboat helped to put out the fire.
