Sixteen undernourished Asiatic black bear cubs have been found in a home in Laos capital Vientiane by a conservation charity, the largest rescue of the year.

The clutch of cubs, also known as moon bears after the white crescent of fur across their chests, are classified as vulnerable on the IUCN Red List of endangered species. 

Across Asia, thousands of the animals are kept as pets or farmed to extract their bile for use in costly traditional medicine.

Wildlife conservation charity Free the Bears said they found 17 cubs in the private home in Laos early last week, but that one of them had already died.

"When we arrived at the house there were bear cubs everywhere," said Fatong Yang, animal manager with the charity.

The group found ten males and six females, weighing between 1.3 to four kilograms and believed to be around two to four months old.

"Cubs this small are extremely vulnerable. In the wild their mothers would never leave them and we suspect the mothers were killed by poachers," Fatong said in a statement over the weekend.

Charity head Matt Hunt said the organisation would have to bring in experts from Cambodia to cope with the number rescued, surpassing a 2019 mission when five cubs were saved in the country's north.

"This is the most bears we've rescued in a single year and we're only three months into 2024," he said.

Free the Bears said that police were alerted to the house after a neighbour heard the cries of one of the cubs.

One Laotian person has been taken into custody, the group said, while police continue to search for the owner of the property.

The cubs have been transferred to Luang Prabang Wildlife Sanctuary, Free the Bears said in a statement, where they will be bottle-fed and closely monitored.

Hunt added that they were "so happy sixteen of the seventeen are alive and have a second chance to live a life free from fear and suffering".