A fire that broke out at a POSCO factory in the southeastern city of Pohang early on Sunday has been put out after five hours.

Fire authorities of North Gyeongsang Province announced on Sunday that the fire, which broke out at the third Finex furnace of the nation's largest steelmaker at 4:20 a.m., was extinguished at 9:20 a.m.

The fire reportedly started with several loud explosions, prompting fire authorities to activate Level One of their emergency response posture at 4:50 a.m. and mobilize 40 fire trucks and 120 personnel to put out the fire.

Eight employees were reportedly working at the factory at the time of the fire, with one of them taken to a hospital with burns.

Police and fire authorities plan to conduct an investigation to find out the cause of the fire and the extent of the damage.