A South Korean vessel that was being constructed by major shipbuilder Daewoo Shipbuilding & Marine Engineering Co. caught on fire Monday on an island south of Seoul, killing two and leaving seven injured, fire authorities said.

Geoje Fire Station said a 39-year-old worker, known by the surname Lee, was found dead at around 5 p.m. in a fuel tank of the 84,000-ton liquefied petroleum gas (LPG) carrier located at Okpo Shipyard on Geoje Island, South Gyeongsang Province, about 406 kilometers south of Seoul.

The body of the victim was discovered about seven hours after the fire broke out at around 9:44 a.m.

Another victim, 30, who had been missing at first, was found dead at around 6:00 p.m., the authorities said. 

Firefighters said 47 workers had been working at the time of the accident.

"It seems that the two did not make their way out," a Daewoo official said.

The fire appeared to have been caused by a welding spark inside the vessel that was being constructed at one of the company's building docks, the firefighters said.

Seven of the workers have been hospitalized for treatment after they inhaled fumes from the fire, while 38 others are confirmed to be unharmed.

The shipbuilder has set up a team to deal with the procedures for compensations and funeral arrangements with the victims'families, it added.

Daewoo Shipbuilding Co. is one of the country's big-3 shipbuilders, along with Hyundai Heavy Industries Co. and Samsung Heavy Industries Co. (Yonhap)