The fire was detected at around 11 p.m. Friday by a group of workers at the electronic manufacturing firm Dreamtech Vietnam at Vietnam Singapore Industrial Park in Tien Du District.
Firefighters were soon dispatched to the scene, but the large fire occuring around midnight made it difficult for rescue operations. The fire was eventually put out an hour later.
Three workers at the company, two men and one woman aged 28, 31 and 32, were killed.
An investigation is ongoing.