Witnesses said they heard a big explosion at Fuse bar near the National Funeral House on Tran Thanh Tong Street at around 02.00pm with thick smoke coming out.

Ten welders were said to be working inside the bar to improve its sound insulation system.

Three fire engines were called in to put out the roaring fire. Fire fighters cordoned off the bar and tried to storm into the building and rescue welders.  

Two of the 10 welders were found dead on the spot, and four others died at Central Military Hospital 108 nearby. The four remaining workers were in hospital for treatment.

Although the fire was extinguished within 30 minutes, the bar was thick with smoke from burning foam and insulating sheets.

A number of fire fighters suffocated after inhaling the hazardous fumes.

Relevant agencies were identifying the cause of the fire.