Firefighters attempt to extinguish the flames from the explosion of a oil storage tank in Ulsan, Feb. 10. Yonhap

An oil storage tank in the southeastern city of Ulsan exploded Monday, leaving one person dead and another injured, officials said.

The explosion took place at a plant in Ulsan, some 310 kilometers southeast of Seoul, at 11:15 a.m., according to fire authorities.

The two people were workers who had opened the tank to check the level of chemical substance inside when the blast occurred.

One worker in his 30s fell unconscious and was taken to a hospital, where he received surgery but was pronounced dead in the afternoon.

The other worker was injured but not in life-threatening condition.

The fire was put out after about three hours as more than 230 firefighters and 44 pieces of equipment, including fire engines, were mobilized for the effort.

Acting President Choi Sang-mok had given emergency instructions to deploy all available resources to extinguish the blaze. (Yonhap)