VIENTIANE, July 25 (Xinhua) -- Lao Prime Minister Thongloun Sisoulith said Wednesday that some 131 people were still missing after a hydropower dam collapsed in southern Laos earlier this week.

The collapse of the under-construction Xepian-Xe Nam Noy hydropower dam triggered flash flood in seven villages of Sanamxay district in Lao's southern Attapeu Province.

He did not mention the exact death toll of the disaster although reports from the Lao New Agency said 26 people were confirmed dead.

The prime minister told a press conference that all villagers stranded on roofs of submerged houses or on trees had been transferred to safe places Tuesday.

"The number of homeless persons has climbed to 3,060 and 131 people are missing. As the flood is still flowing, another five to six villages are now being affected by the flood," he said.

Thongloun said authorities were helping victims in the villages affected by the flood.

The prime minister added a special committee was established to deal with the situation and it would cooperate with relevant departments to investigate the the incident.

He also thanked the international community in helping the rescue work.

Initial reports said several were killed and hundreds missing following the dam collapse in the landlocked country.?