The Indian embassy says it has set up control rooms to respond to victims’ families.

Fifteen Indian tourists have died after their speedboat capsized near southern Vietnam’s Phu Quoc island.

Authorities confirmed the incident on Saturday and said the boat was carrying 32 Indian tourists and four crew members when it overturned. A total of 21 people were rescued and those injured have been hospitalised.

The cause of the accident is not yet known.

Local media reported that the speedboat had left the popular Hon May Rut Ngoai island after noon on Saturday and was returning to the An Thoi International Port when the accident occurred – about 400 metres (a quarter of a mile) from the tourist location.

Social media photos appeared to show the moments when rescuers pulled victims out of the water and attempted to revive them. Witnesses told the VN Express news site that nearby boats rushed to the scene of the accident and began pulling out the passengers before Vietnamese border guards, navy and the coastguard arrived.

Many of the victims were trapped inside the vessel, making the rescue difficult, VN Express reported.

In a statement, India’s embassy in Hanoi said rescue operations by local Vietnamese authorities were continuing and that it had set up control rooms in the capital and in Ho Chi Minh City to coordinate with the victims’ families.

“Exact details of the incident are being ascertained,” the embassy said.

Last July, tourist boat Wonder Sea capsized in Ha Long Bay during a thunderstorm. A total of 39 people were killed in the incident – one of Vietnam’s deadliest sea accidents.

Phu Quoc, located in the Gulf of Thailand, is among Vietnam’s best-known beach destinations. Hon May Rut Island is located about 10km south of Phu Quoc. Both draw millions of tourists yearly to their white sand beaches and clear green waters.