SEOUL -- Twenty-two people were confirmed dead and eight others were injured in South Korea's battery plant fire on Monday, according to the fire authorities.

The fire broke out at a primary battery plant in Hwaseong, around 45 km south of the capital Seoul, at about 10:31 am local time (0131 GMT).

Kim Jin-young, a local fire station official, said in a televised briefing that rescue workers retrieved the bodies of the 21 missing factory workers who had failed to be reached after the fire outbreak.

Ahead of the search operation inside the ill-fated plant, one worker died after having been found in cardiac arrest.

Two others were seriously wounded, while six suffered minor injuries such as smoke inhalation.

One worker remained unaccounted for, but it was not clear whether the worker had been trapped inside the factory or simply not reached, according to the fire official.

Firefighters struggled to extinguish the fire because of the difficulty in putting out the flame of lithium batteries.

They went inside the factory and searched the bodies after extinguishing a large blaze at about 3:10 pm local time (0610 GMT).

Some 35,000 lithium batteries were estimated to be stored on the second floor of the three-story reinforced concrete factory with a total floor area of 2,300 square meters or so.

The victims were believed to have failed to escape through stairs to the ground.