Heavy monsoon rains unleashed flash floods and mudslides in northern Thailand which killed at least 34 people, left dozens missing and thousands homeless, officials said on Tuesday.
Unusually heavy rain at the start of the monsoon lashed deforested hills, causing flash floods - some of them three metres (10 ft) deep - which swept into cities and towns in four provinces, they said.
The region is not a key farming area for Thailand, the world's biggest exporter of rice, tapioca and rubber, but Prime Minister Thaksin Shinawatra will fly to inspect the areas on Wednesday, a day after he formally took back the reins of power.
Uttaradit, 500 km (310 miles) north of Bangkok, was the worst hit province where 30 bodies were already found and the toll could rise beyond 100 as many bodies were believed to be buried under the mud or washed away by the waters, officials said.
"From what we've seen at the affected sites, we believe the toll will rise to a hundred as many might have still been buried under the mud," said Eadyoungone Yongyuan, a deputy chief provincial doctor of Uttaradit told Reuters by telephone.
Most of the deaths were believed to have occurred in the Laplae district of Uttaradit province, where 330 mm (13 inches) of rain fell in the 24 hours to 0000 GMT on Tuesday, causing mudslides, officials said.
Hundreds of students, including 20 from China, could not leave their college where the water was three metres (yards) deep as rescue workers rowed boats to pass them food and look for sick people to take to hospital.
Earlier on Tuesday, 700 inmates from Uttaradit central prison were transferred to other prisons in nearby provinces as water was about to flood their cells, state Radio Thailand reported.
All rail traffic between Bangkok and the north was cancelled after four trains, carrying about 1,000 passengers, were stranded in Uttaradit.