Sixteen people, including six children, died when a double-decker tour boat hosting a child's birthday party sank on the Sai Gon River, dpa quoted officials as saying Saturday. The boat was carrying 21 people when it sank amid heavy rain and strong winds on Friday night. The party was organized by director of an electric cooker company for his three-year-old son, state media reported. The child, two of his siblings and their mother were among the dead. Witnesses said the boat sank just five minutes after it dropped anchor, about 100 metres from the shore. Three people in connection with the tragedy, including the manager of the company that owns the boat. Authorities said the vessel's registration had expired on January 28. In February, 11 holidaymakers and their guide drowned in one of the worst accidents of its kind in Vietnam involving foreign tourists when their boat sank. Earlier this month a boat carrying 28 French tourists sank, with no fatalities.