
The explosion Tuesday afternoon immediately killed Pham Van Nghia, 30, his wife Le Thi Tai, 28, and their 3-year-old son Pham Van Thanh at their house in Quang Nam province, 820 kilometres south of Hanoi.
"It was a shell of 130 millimetres in diametre left from the war against the Americans," said Diep Tan Luc, an official with the People's Committee of the province's Duy Nghia commune, where the accident happened.
The explosion happened when Nghia was cutting the shell with a saw, intending to remove the explosive inside and sell the shell as scrap metal, Luc said.
War-time ordinance has killed at least 10 people in Vietnam over the last two months, including four children.
Dozens of Vietnamese are killed every year by bombs, mines, or grenades, most of which are remnants of the Vietnam War - called the American War locally.
//Deutsche Presse-Agentur