Posco Pohang Steelworks in Pohang, North Gyeongsang Province (Yonhap)
Posco Pohang Steelworks in Pohang, North Gyeongsang Province (Yonhap)

Three workers fainted after inhaling what appeared to be toxic gas at Posco's steel mill in Pohang, North Gyeongsang Province, on Thursday, officials said.

The accident occurred around 1:30 p.m. at the steelworks in Pohang, 262 kilometers southeast of Seoul, while two contracted cleaners and a Posco employee were removing sludge, they said.

All three were taken to hospitals, including two who were found in cardiac arrest.

Firefighting authorities cited carbon monoxide poisoning as a possible cause.

The accident comes only two weeks after one worker was killed and three others suffered burns after becoming exposed to chemical substances from damaged pipes. (Yonhap)