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

North Korea announced early on Wednesday it had successfully conducted a hydrogen nuclear test.

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.