The death toll reached 59 Saturday from floods and mudslides in southern Thailand over two weeks that caused damage estimated at more than 300 million dollars, officials said.

The Interior Ministry's disaster prevention and mitigation department said 26 people had died in Nakhon Si Thammarat province, 610 kilometres south of Bangkok.

Twelve deaths were confirmed in neighbouring Surat Thani province, with additional casualties in Krabi, Phatthalung, Chumphon, Trang and Phangnga provinces throughout the southern region.

Large areas of Nakhon Si Thammarat were reported still underwater on Saturday.

'The damage bill could reach nearly 10 billion baht (333 million dollars),' the Bangkok Post quoted Prime Minister Abhisit Vejjajiva as saying.

While life was returning to normal in much of the flood zone, Abhisit said floodwaters could take up to nine more days to drain from the hardest hit areas in Nakhon Si Thammarat.

The heavy downpours stranded thousands of tourists on Samui, an island in the Gulf of Thailand popular among Western tourists.

The island's airport and ferry services were closed down for three days at the height of the storms, but resumed operations Wednesday.

Meteorologists blamed the unusually heavy storms on a high pressure front from China and La Nina, a three-to-six-year climatic phenomenon.