At least 15 people were killed after a tourist boat capsized off the coast of one of Vietnam’s most popular island destinations.

The deadly incident happened near Phu Quoc at around 1 p.m. local time on Saturday, July 11, according to Vietnam News and Reuters.

There were 32 Indian tourists and four crew members on board the boat when it overturned.

The group had reportedly been traveling from Hòn Mây Rút Ngoài back to An Thới Port when the vessel capsized less than a mile from Hòn Mây Rút Ngoài Island, according to VN Express.

The boat was reportedly operated by the Ocean Pearl Island Company. Officials said the vessel overturned amid high waves and strong winds.

Emergency crews rushed to the scene after the boat went down.

According to Vietnam News and VN Express, 21 survivors were taken to medical facilities for treatment. Two of them were reportedly in critical condition.

Nguyen Tien Hai, Secretary of the An Giang Provincial Party Committee, said rescuers were focused first on saving lives and getting victims back to shore.

“The top priority is rescue, bringing all victims ashore and focusing all efforts on providing emergency care to those who are still alive,” he told VN Express.

Authorities have launched an investigation into what caused the boat to capsize.

A report on the tragedy has also been submitted to Vietnam’s Prime Minister, the Ministry of Foreign Affairs, and the Ministry of Culture, Sports and Tourism, according to Vietnam News.

The Embassy of India in Hanoi said local authorities were still working to determine exactly what happened.

“Exact details of the incident are being ascertained as search and rescue operations by local authorities are ongoing,” the embassy wrote on X.

The tragedy unfolded near Hòn Mây Rút Ngoài, a popular tourist spot in Phu Quoc. The area is known for its clear blue water, white sand, and postcard-like scenery.

Visitors typically reach the island destination by boat in about 20 to 40 minutes, according to VN Express.

Phu Quoc is Vietnam’s largest island and has long been a major draw for travelers looking for beaches, boat tours, and tropical scenery.

The Embassy of India in Hanoi did not immediately respond to PEOPLE’s request for comment. The Ocean Pearl Island Company also did not immediately respond.

Search and rescue efforts remained ongoing as officials continued to investigate the deadly capsizing.