The bus was carrying 44 Chinese and two Laotians—a driver and a guide—when it skidded of the road and plunged into a ravine late Monday, prompting a rescue operation in a mountainous area where road conditions are poor.
The bus was traveling from Vientiane to Luang Prabang, an ancient capital and a UNESCO World Heritage Site popular with tourists some 180 miles (300 kilometers) north from the capital.
The number of Chinese visitors to Laos has grown in recent years from more than 500,000 in 2015 to 600,000 in 2017, and more than 800,000 in 2018, according to official data.
Laotian authorities has not determined the cause of the accident, the state-backed Vientiane Times reported.
By Panu Wongcha-um