According to a report by Vietnam News, the boat was carrying 32 Indian tourists and four crew members.

Local authorities said the vessel, operated by Ocean Pearl Island Company, was transporting the tourists from Mây Rút Ngoài Island back to An Thới Port when it suddenly capsized amid strong waves and winds, throwing everyone on board into the water.

Police, military and medical personnel, along with rescue vehicles, were quickly deployed to the scene. Twenty-one people were rescued and rushed to hospital, the report said.

Mây Rút Ngoài Island is a popular tourist destination in Vietnam.

Confirming the incident, the Indian Embassy in Vietnam wrote on Facebook: "In a tragic incident, a boat carrying several Indian tourists has capsized near Phu Quoc Island in Vietnam a few hours ago."

"Exact details of the incident are being ascertained as search and rescue operations by local authorities are ongoing," the Embassy said.

To provide information and assistance to affected families, a Control Room has been set up at the Consulate General of India in Ho Chi Minh City. It can be reached at +84 36 281 7930, +84 91 552 37 14 and +84 33 452 0414.

A separate Control Room has also been established in Hanoi and can be reached at +84 91 308 9165.