Bangkok: Hundreds of people are missing and several are feared dead after a hydropower dam under construction in Laos collapsed, causing flash flooding which swept away homes, local media reported on Tuesday.

Officials have brought boats to help evacuate people in San Sai district of Attapeu province, where the Xepian-Xe Nam Noy hydropower dam is located, as water levels rise after the collapse, ABC Laos news reported.

The company building the dam said heavy rain and flooding caused the collapse and it was cooperating with the Laos government to help rescue villagers near the dam.

‘We are running an emergency team and planning to help evacuate and rescue residents in villages near the dam,’ a SK Engineering & Construction spokesman told Reuters by telephone.

The dam collapsed at 20.00 hours on Monday releasing 5 billion cubic metres of water and several hundred people are missing and homes have been swept away, the Lao News Agency said. It said several people had died.

Communist Laos, one of Asia’s poorest and most secretive countries, aims to become the ‘battery of Asia’ by selling power to its neighbours through a series of hydropower dams.

Environmental rights groups have for years raised concerns about Laos’ hydropower ambitions, including worries over the impact of dams on the Mekong River, its flora and fauna and the rural communities and local economies that depend on it.