NAKHON SI THAMMARAT (Thailand) • This time of year, the resorts and beaches of Thai islands Koh Samui, Koh Phangan and Koh Tao are packed with thousands of holidaymakers and revellers from around the world enjoying the New Year holiday break.

The islands are among Thailand's most popular destinations and key earners for the country's lucrative tourism trade.

Yesterday, the beaches were empty as Tropical Storm Pabuk lashed the area with heavy rain and pounding surf, triggering blackouts. Thousands of tourists and residents fled before the storm's arrival, while those marooned hunkered down to wait out Thailand's first tropical storm in three decades as it struck during the peak holiday season.

"Ten thousand tourists are still on Koh Phangan," said Mr Krikkrai Songthanee, district chief of the island which neighbours Samui and is famed for its full-moon parties.

"But I talked to foreigners last night and they are not scared, they understand the situation," he told Agence France-Presse (AFP).

Meteorologists said Pabuk made landfall in southern Thailand yesterday afternoon, sparing the tourist islands to the north from a direct hit.

"But all tourist islands in the Gulf of Thailand, including Koh Samui, Koh Phangan, Koh Tao, will be affected because Pabuk is huge," said Mr Phuwieng Prakhammintara, head of the Thai Meteorological Department.

Tens of thousands of tourists have already fled the southern zone.

"It is very empty... The beaches are deserted," Koh Phangan resident Pui Suriwan told AFP.

On neighbouring Koh Tao, one of South-east Asia's most popular dive spots, tourists and residents were bracing themselves for a torrid 24 hours. "I have finished buying supplies... There is no gas anywhere on the island, 7-Eleven is already running out of things," a Spanish dive instructor told AFP.

"We are ready to hunker down."

Holidaymakers on Koh Samui, whose airport was shut yesterday, shared videos on Twitter of waves licking the steps to beachside bungalows as the wind speeds picked up.

"It is quite scary being here because we don't know what is going to happen and there is no way to leave," American tourist Miranda Abidyer, 26, who is stranded on Koh Samui, told CNN.

Ms Abidyer, who travelled to the island with her young family to celebrate her husband's 30th birthday, said they had a flight scheduled for yesterday but it was cancelled, and ferry services have also been suspended. She said they had not received any information from the local authorities about the storm or what they should do. They said they would wait out the storm in their private villa, which is about 1km from the beach.

"We will hide in the bathroom if the storm gets that bad. But all we can do is wait," said Ms Abidyer.

The district chief of Koh Samui, Mr Kittipop Roddon, told CNN by phone yesterday that there were about 20,000 tourists staying on the island, which is the second-largest in Thailand.

"The island is now totally cut off from the mainland, all kinds of transportation (to the mainland) have been suspended since yesterday," he said, adding that there is enough food and supplies on Koh Samui to last through the storm.

The storm is forecast to weaken as it crosses over from the Gulf of Thailand to the Andaman Sea, but tourists have been warned to be prepared for heavy rain, rough seas and landslides.

In 1989, Typhoon Gay killed hundreds in southern Thailand. The storm swept in from the Gulf of Thailand, crossed into the Andaman Sea, then struck eastern India several days later.