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.

A Vietnamese man who survived the capsizing of a tour boat in Ha Long Bay said he escaped the overturned vessel by swimming out through a window underwater

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.