A fire at a yard in Batam, Indonesia, killed five people and injured one more.
The incident was revealed in a statement from the board of directors of ASL Marine Holdings Ltd.
A fire broke out on board a tanker which was in a dry dock, killing the subcontractors of the shipbuilders.
Initial investigations suggest that there was no explosion.
A statement from ASL Marine Holdings said: “We are saddened by this incident and the loss of lives, and we extend our deepest condolences to the families of the victims.
“As a matter of priority, we will be working diligently together with our subcontractor to help the affected workers and their families and are rendering the necessary assistance to them.
“The investigation will continue and until the cause is established, work on this vessel will be suspended.
“We are also co-operating with the authorities in Indonesia to establish the cause of the fire.”