The yacht, carrying 39 people on board overturned at around 9:00 a.m. local time (0200 GMT) on Sunday when caught by a sudden storm hitting the capital area with strong wind, thunder and fairly heavy rain.
On Sunday (April 4), it was reported that the people on board included former Lao president Choummaly Sayasone and his family and friends.
Witnesses told Xinhua via phone that a search and rescue operation has been carried out.
According to rescue staff and sources close to the Choummaly family, Choummaly was found alive and rushed to the hospital, his youngest son and two daughters were also rescued, while four bodies have also been recovered and five more people were still missing, till 4:00 p.m. local time (0900 GMT).
Choummaly, born on March 6, 1936, was the General Secretary of the Lao People's Revolutionary Party (LPRP) and President of Laos from 2006 to 2016.
Nam Ngum Lake, some 60 km north of Vientiane, is a weekend outing destination for Vientiane residents.
KPL report quoted Khamphan Sithidampha, the governor of Vientiane province, as saying that the boat sank about 40 metres off the shore due to the strong wind. Search and rescue operations were carried out immediately after the incident occurred.
By 16:30 local time (0930 GMT), a total of 31 survivors had been rescued and taken to the hospital, with eight bodies recovered. - Xinhua