Local policemen, medical staff and rescuers rushed to the scene after the incident took place at 1.50pm. They took the injured to nearby hospitals for treatment, while the bodies of the two workers were kept for autopsy.
Investigators suspect the explosion was caused by a thinner vapour and welding machine spark, as one group of workers were painting metal sheets for shipbuilding, while another group nearby welded a pier.
The victims were hit by metal sheets due to the explosion, Bang Sai Police Station investigators said, adding that the cause of the incident was being probed.