Hundreds of people are missing and many feared dead after a partly constructed hydropower dam collapsed in southeast Laos.
The disaster triggered flash floods in six villages, state media said on Tuesday.
Laos is traversed by a vast network of rivers and there are several dams being built or are planned in the landlocked country, which exports most of its hydro energy to its south-eastern Asian neighbours.
Laos News Agency said the accident happened at a hydropower dam in Attapeu province's Sanamxay district late on Monday, releasing five billion cubic metres of water – equivalent to more than two million Olympic swimming pools – and resulting in flash flooding.
The report added that there were "several human lives claimed, and several hundreds of people missing".
Images published in the report showed scores of people, some clutching young children, crammed onto low-slung wooden boats and wading through muddy waters.
Several houses in the southern part of the district were swept away following the dam's collapse around 8pm (5pm UAE) on Monday evening, the report said, as officials in the province put out a call for relief aid for flood victims.
"We do not have any formal information yet about any casualties or how many are missing," an Attapeu official said on condition of anonymity, adding that was "no phone signal" in the flooded region.
"We sent rescue teams who will help them and provide basic assistance first," the official added.
The $1.2 billion dam is part of a project by the Xe Pian Xe Namnoy Power Company (PNPC), a joint venture formed in 2012.
Among the companies involved in the project, according to the Laos News Agency, are Thailand's Ratchaburi Electricity Generating Holding, South Korea's Korea Western Power and the state-run Lao Holding State Enterprise.
The 410-megawatt capacity dam was supposed to start commercial operations by 2019, according to the venture's website.
The project consists of a series of dams over the Houay Makchanh, the Xe-Namnoy and the Xe-Pian rivers in neighbouring Champasak Province.
It planned to export 90 per cent of its electricity to Thailand and the remaining amount was to be offered up on the local grid.
Under the terms of construction, PNPC said it would operate and manage the power project for 27 years after commercial operations began.
When contacted by phone in the Laos capital of Vientiane, a company official said: "We do not have any official reports about it yet. We are gathering information."
