By Amy Sawitta Lefevre
BANGKOK (Reuters) - Rescuers searched floodwaters on Wednesday for dozens of people feared dead and hundreds missing after a dam collapsed in a remote part of land-locked Laos, one of Asia's poorest countries, a government official said.
State media showed pictures of villagers, some with young children, stranded on the roofs of submerged houses. Others showed villagers trying to board wooden boats to safety in Attapeu province, the southernmost part of the country.
At least seven villages have been submerged. State media pictures showed one-storey homes flooded with muddy water.
A senior Lao government official, who declined to be identified because he was not authorised to speak to the media, said dozens of people were feared dead and hundreds remain unaccounted for after the hydropower dam that was under construction collapsed on Monday.
"We will continue with rescue efforts today but it's very difficult, the conditions are very difficult. Dozens of people are dead. It could be higher," the Vientiane-based official told Reuters by telephone.
But the remoteness of the affected area could hamper relief operations, say experts.
For graphic on map locating the collapsed dam in Laos click https://tmsnrt.rs/2JLQY4F
The once-isolated Southeast Asian country, one of the world's few remaining communist states, has an ambitious dam-building scheme in order to become the "battery of Asia".
Its government depends almost entirely on outside developers to build its planned portfolio of dams under commercial concessions that agree to export electricity to its more developed neighbours, including power-hungry Thailand.
Environment rights groups have repeatedly warned about the human and environmental cost of the rapid pace of dam construction, including damage to the already-fragile ecosystem of the region's rivers.
Attapeu is a largely agricultural province that borders Vietnam to the east and Cambodia to the south.
The dam that collapsed is part of the hydroelectric Xe-Pian Xe-Namnoy power project, which involves Laotian, Thai and South Korean firms. The subsidiary dam, known as "Saddle Dam D", was part of a network of two main dams and five subsidiary dams.
South Korea's SK Engineering & Construction said part of a small supply dam was washed away and the company was cooperating with the Laos government to help rescue villagers near the site.
The firm blamed the collapse on heavy rain. Laos, and its neighbouring countries, are in the middle of the monsoon season when tropical storms and heavy rain can lead to flash floods.
An official at the firm said fractures were first discovered on the dam on Sunday and that the company had ordered the evacuation of 12 villages as soon as it became clear the dam could collapse.
Shares in major stakeholders of SK Engineering & Construction fell on Wednesday after news of the collapse.
SK E&C's biggest shareholder, SK Holdings Co Ltd, was down 6.2 percent, marking its biggest daily percentage loss since February 11, 2016. The second biggest shareholder, SK Discovery Co Ltd, slid as much as 10 percent.
Ian Baird, associate professor of geography at University of Wisconsin-Madison and a Laos expert, said the collapse of the subsidiary dam was unlikely to affect others in the project, but added that the dam can't be fixed until the dry season.
"I don't think its going to affect the other dams," Baird told Reuters in a telephone interview.
"The water's all out of the reservoir now and the water levels are already going down but I don't think they'll be able to fix it until the dry season," he said.
The remoteness of the affected area and damage to roads and bridges will make it very difficult to reach those still stranded, he said.
"The roads are very poor in that area. People don't usually go in that area during the rainy season. There are mountains nearby that villagers might be able to get up on .... I don't think anybody really knows for sure," he said.
(Additional reporting by Fanny Potkin in JAKARTA and Heekyong Yang in SEOUL; Editing by Paul Tait and Michael Perry)