A boy survived the sinking of a tourist boat in Vietnam which killed dozens of people by sheltering in an air pocket of the overturned vessel, it has emerged.

The boat, carrying 46 passengers and three crew members, was on a sightseeing tour of Ha Long Bay when a sudden storm caused it to overturn, state media said. Ten people were rescued.

A tourist boat capsized during a sudden thunderstorm in Vietnam on Saturday afternoon during a sightseeing excursion, killing at least 34 people and prompting a search for others who remain missing, state media reported.