South Korea says small amount of hydrogen may have been injected in North's device

SEOUL (Reuters) - South Korea's defense ministry said a small amount of hydrogen may have been added to a device North Korea tested on Wednesday, media reported. "We will find out after closely analyzing it but we understand a small amount of hydrogen may have been added to the fourth nuclear test," ministry spokesman Kim Min-seok told reporters, according to the MoneyToday online news service. North Korea announced early on Wednesday it had successfully conducted a hydrogen nuclear test. (Reporting by Seyoung Lee and Jee Heun Kahng, Ju-min Park; Editing by Robert Birsel)