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 48 passengers and five crew members, was on a sightseeing tour of Ha Long Bay when a sudden storm caused it to overturn, state media said. At least 10 people were rescued.

The incident happened in Vietnam's popular Ha Long Bay during bad weather, with five people still missing, local reports say.