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

South Korean Defense Ministry spokesperson Kim Min-seok speaks on the outcome of a government investigation into three unmanned drones, recently found near the inter-Korean border areas, during a news conference at the ministry in Seoul, May 8, 2014. REUTERS/Ahn Young-joon/Pool/Files

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)