VIENTIANE, July 25 (Xinhua) -- At least seven bodies had been recovered and 20 villagers remained missing after an under-construction dam collapsed in southern Laos, the Lao government website reported on Wednesday.

The collapse of the Xepian-Xe Nam Noy hydropower dam triggered flash flood in eight villages of Sanamxay district, in Lao's southern Attapeu Province. Some 4,283 people of 1,005 households in the villages were affected by the flooding, the website said.

The seven bodies recovered were from the village of Mai and 20 missing from the village of Saydounkeng. Rescue personnel were still collecting the number of casualties from other six villages.

Video clips and photos on social media showed flood-water levels going up to the ceiling, forcing villagers and animals to seek shelter on rooftops.

Initial reports said several were killed and hundreds of villagers were missing in the landlocked country.