SEOUL, Oct. 17 (Xinhua) -- Five workers were injured on Friday from a hydrogen pipeline explosion at a refinery plant in southeastern South Korea, according to local broadcaster YTN.
The pipeline explosion occurred at the plant of local refiner SK Energy in Ulsan, around 300 km southeast of Seoul, at about 10:40 a.m. local time (0140 GMT).
Five workers were wounded, four of whom suffered serious injuries.
The plant's hydrogen production facilities had been undergoing regular maintenance since Wednesday.
It was estimated that the hydrogen gas remaining in the pipeline caught fire while the pipe was being opened.
Police and fire authorities were investigating the exact cause of the accident. ■
