The boat, carrying 53 people, tipped over at around 2pm local time (0700 GMT), as Storm Wipha approached the country across the South China Sea. Strong winds, heavy rainfall and lightning were reported in the area.

Most of the tourists were from the capital, Hanoi, local newspaper VnExpress reported. There was no official announcement on the nationality of the tourists as emergency crews kept looking for survivors.

Rescue teams found 11 survivors and recovered 27 bodies, eight of them children, the state-run Vietnam News Agency said, citing local authorities.

Halong Bay, about 200 km (125 miles) northeast of Hanoi, attracts tens of thousands of visitors every year. Boat tours are hugely popular.

Storm Wipha, the third typhoon to hit the South China Sea this year, is projected to make landfall along Vietnam’s northern coast early next week.

Weather linked to the storm also disrupted air travel. Noi Bai Airport said nine arriving flights were diverted to other airports, and three departing flights were temporarily grounded on Saturday.