Two machinists were killed and three severely injured in Da Nang on Saturday, after an oxy-fuel welding container exploded.
Tran Ngoc Long, 56, and Ly Thanh Tho, 44, were killed on the spot. Three of their co-workers were thrown by the powerful explosion, which punched holes in the walls and ceiling of the factory.
The victims had been hired by a private local firm run by Dang Cong Hung, 56, to repair on bulldozers and excavators.
Police are investigating the cause of the explosion.