Four men were killed Sunday following an explosion aboard a product tanker under construction at South Korea’s STX Offshore & Shipbuilding.

The men, aged between 33 and 53, were said to be carrying out painting work on the ship, an official from the National Fire Agency was quoted as saying.

South Korean media said the explosion took place at around 11.37 am in one of the vessel's tanks. However, TradeWinds was unable to confirm this.

The 74,000-dwt tanker was reportedly due to be delivered to Greek shipowner Andriaki Shipping in October this year.

The local police and fire authorities said they are currently investigating the details of the accident including the cause.

In May this year six people were killed and more than 20 injured when a crane collapsed at Samsung Heavy Industries.