Six Western tourists and two Thai guides have died after flash floods swept them away while exploring a cave at a national park.
The victims were determined by Thai police on Sunday to be a Swiss couple and their two daughters, a British man and a ten-year-old German boy. The Swiss foreign ministry confirmed on Sunday evening that four Swiss had died.
The group had been trekking through the Khao Sok National Park in Surathani province, 650km south of Bangkok and 180 north of Phuket, on Saturday afternoon when a heavy rainfall caused flash floods that sent water surging through the cave, which was near a waterfall, said Lt. Col. Pichan Kanayasiri.
"The tourists were inside the cave [in a little boat] and didn't know what was happening outside," Pichan said. "They were trapped inside the cave."
A British woman, who survived by clinging to the ceiling of the cave for 20 hours, was found alive after a long search, Pichan said. It was not immediately clear if there had been any more tourists in the group.
The province's governor, Winai Phopradit, said he had ordered the national park to close during the monsoon season, which lasts until the end of October.
"We have signs both in English and Thai warning tourists not to go into the cave during heavy rains," he said.
Khao Sok National Park is covered by the oldest evergreen rainforest in the world and is a popular destination for tourists staying on the island of Phuket. Last year more than 20,000 people visited the park, which is known for its birds and butterflies.
Thailand is a popular travel destination for the Swiss, with 150,000 visiting the country every year, although the main influx of tourists from Switzerland does not get underway until November.
In September economists at Credit Suisse said they expected demand to continue for destinations abroad with the strongest growth region likely to be Asia, although demand for European and US travel would remain brisk.
The most favoured destinations were likely to be Thailand, the United States and China. In Europe, Greece, Spain and Croatia come out on top.
Analysts said tourists were returning to Thailand because the country had rebuilt itself after the devastating tsunami of 2004.
Not just tourists
However, an increasing number of Swiss are buying one-way tickets to Thailand. The latest figures from the Swiss foreign ministry show Asia is proving to be a favoured destination of migrants.
The Swiss community grew by 12.8 per cent in China last year, ten per cent in Thailand and 21 per cent in Singapore.
Economically Thailand is an important trading partner for Switzerland, and Swiss exports to the country have trebled in the past decade to SFr934 million ($787 million). Over the same period Swiss imports from Thailand have almost doubled to SFr723 million.
Asian nations' strong economies have done much to attract the Swiss. But there are others who have headed to countries such as Thailand and the Philippines in search of a warmer climate and a cheaper lifestyle for their retirement.
swissinfo with agencies
4,000 Swiss live in Thailand.
150 Swiss firms do business in Thailand.
150,000 Swiss tourists visit Thailand every year.
Swiss exports to Thailand have trebled in the past decade to SFr934 million ($746 million).
Swiss imports from Thailand have almost doubled over the same period to SFr723 million.
Thailand is Switzerland's second-largest trading partner in the region, after Singapore.
Switzerland is also well-known in Thailand since King Bhumipol spent seven years of his childhood in Switzerland.