Three people were killed in an explosion that occurred at a plant operated by South Korea‘s top steelmaker, Posco, on Tuesday, fire officials said.

The incident took place at around 4 p.m. with a roaring sound at its plant in Gwangyang, 420 kilometers southwest of Seoul, involving a blaze that was put out in about 20 minutes, according to the officials.

Authorities said the explosion appears to have started near a furnace while workers were handling high-pressure gas, adding that they are looking into the exact cause of the incident. (Yonhap)