Deadly blast in Hanoi allegedly caused by man opening bomb with blow torch, police said   The large crater caused by the blast in Hanoi on March 19. Photo: Minh Chien The Ministry of Public Security has found traces of explosives and bomb debris at the site of a blast in Hanoi on Saturday that killed four people, injuring 10 others and damaging more than 120 houses. The explosion at about 3.10 p.m. at a scrap metal trading business seriously tore through 36 houses and damaged 95 others, and left a large crater in Van Phu residential area, Ha Dong District, the police said. Many vehicles along the street were damaged too. Although the police was yet to officially pinpoint the cause of the blast, they speculated that it was ignited when the shop owner tried to cut open a bomb by gas welding. One of the perished victims was Pham Van Cuong, 42, who had rent the house for his scrap metal shop since 2013 and reportedly often used a blow torch to cut large scrap metal pieces, police said. On March 19, he asked a neighbor to help him bring a rusty cylinder to the sidewalk and then used a blow torch to cut it open. “High temperature from the blow torch has ignited the explosion with extremely serious consequences,” VnExpress quoted a report by Hanoi Police Department as saying. Police found metal debris of what they believe to be a bomb. The scene after the blast in Hanoi on March 19. Photo: Minh Chien By Ha An - Minh Chien, Thanh Nien News