Eight tourists, including one Briton, have died after being swept away by flash floods in Thailand while exploring a cave.

The tour group were trekking through the Khao Sok national park in Surat Thani province when the cave flooded.

The dead have not been officially identified but reports say they were two Thai guides, a British man, a German boy and four Swiss nationals.

One person, believed to be a 17-year-old British girl, survived.

The UK Foreign Office confirmed one Briton had died and one had survived but would give no further details as next of kin had not been informed.

According to the Bangkok Post newspaper the seven western tourists and their guides had travelled by boat from Ratchapraphra dam to the cave on Saturday.

The area inside the cave was flooded following a heavy downpour, which began about an hour before the party began their journey, it said.

'Trapped'

The Khao Sok national park in Ban Ta Khun district, which lies 650km (400 miles) south of Bangkok.

According to police Lieutenant Colonel Pichan Kanayasiri the heavy rainfall caused flash floods, which sent water surging into the cave, which was near a waterfall.

The survivor is an Englishwoman. She was able to climb up to the roof of the cave, that is why she survived
Sitichai Thaicharoen
District official

"The tourists were inside the cave and didn't know what was happening outside. They were trapped inside the cave," Lt Col Pichan told news agency AFP.

District official Sitichai Thaicharoen said an English woman was rescued on Sunday after being found clinging to the cave's roof.

She is now being treated in hospital.

"The survivor is an Englishwoman. She is so far fine. She was able to climb up to the roof of the cave, that is why she survived," Mr Thaicharoen told AFP.

Other reports said the woman was aged 17 and the German boy was 10, although the authorities have not confirmed the nationalities or identities of any of those involved.

'Warning'

A senior Thai government official is due to travel to the Surat Thani province on Sunday to begin an investigation into the incident, the Bangkok Post reported.

Chalermsak Wanichsombat, director-general of National Park, Wildlife and Plant Conservation Department told the paper that officials at the park had warned tourists not to travel because of heavy downpours in the area.

A Belgian tourist was killed by a flash flood in the same cave several years ago.

The province's governor, Winai Phopradit, told the Associated Press news agency he had ordered the national park to close during the current rainy season.

"We have signs both in English and Thai warning tourists not to go into the cave during heavy rains," he said.