North Korea launched what appeared to be a second intermediate-range Musudan missile on Wednesday morning after another launch hours earlier failed, South Korea's military said, Reuters reported.
It was not immediately clear if the second launch, about two hours after the first, was successful.
The first missile was launched from the east coast city of Wonsan, a South Korean official said, the same area where previous tests of intermediate-range missiles were conducted, possibly using mobile launchers.
The launches were in continued defiance of international warnings and a series of U.N. Security Council resolutions that ban the North from using ballistic missile technology, which Pyongyang rejects as an infringement of its sovereignty.
Japan said after the first launch that it would protest strongly because it violated a United Nations resolution, Kyodo news agency reported, citing a government statement.