On the same day when North Korea launched a long-range rocket on Feb. 7, South Korean Navy retrieved parts believed to be its debris from the far southern part of Korean peninsula, NBC News has learnt.

North Korean state media said Pyongyang has "totally succeeded in launching the fourth Kwangmyongsong satellite," but the launch was widely seen as a cover for testing ballistic missile technology.

Meanwhile, South Korean Navy is still analyzing the debris, trying to confirm if the so-called satellite is actually a ballistic missile.

