At least one body has been recovered, and Vietnamese authorities have reportedly rescued nine people, the provincial administration of Preah Sihanouk said on its Facebook page.
Vietnamese newspaper Mot The Gioi reported that nine people were rescued late Friday off the Vietnamese island of Phu Quoc, citing authorities there.
Chinese Ambassador Wang Wentian and Preah Sihanouk Provincial Governor Kuoch Chamroeun visited some of the 21 survivors found by Cambodian rescuers on Saturday, the provincial government said.
Authorities said the boat sank early Thursday off the town of Sihanoukville, popular with tourists and gamblers.
The cause of the sinking was not specified. The authorities questioned the survivors, who were taken to a nearby island.
The provincial government gave no details on the identity of the Chinese nationals, and it was unclear whether Cambodians were among those rescued or missing.
Cambodia is popular with Chinese tourists and business people, but many Chinese have been unable to travel in the past two years due to China’s COVID-19 restrictions.
One of the survivors, Chengui Sheng, 27, from China’s Fujian province, told authorities the boat was carrying 41 people, including three women, the provincial government said.
Sihanoukville is home to several casinos and the town has also been the scene in recent years of police raids on suspected cybercrime operators, some with links to China, police said.