The Democratic People's Republic of Korea (DPRK) conducted an ejection test for a submarine-launched ballistic missile (SLBM) last month after carrying out one such test in November, South Korea's Yonhap news agency reported Wednesday citing a military official.

The DPRK's SLBM was believed to have been tested in an initial phase as it was an ejection test, not a full flight test. Under the ejection test, the missile flies just hundreds of meters after being ejected from waters.

The Seoul military official was quoted as saying that the December test has not seemed to be a success, noting that the DPRK has continued such ejection tests.

The DPRK staged a same ejection test on Nov. 28 last year, which was believed to have failed as it didn't soar from the waters. At the time, some of the debris from the missile was found on the ocean surface.

A US media cited a US military official as saying Tuesday that the DPRK's ejection test was staged on Dec. 21 in the East Sea.

The ejection tests in November and December indicated an advance in the DPRK's SLBM technology.

Pyongyang officially announced its successful test-launch in May of a ballistic missile from a submarine, overseen by top DPRK leader Kim Jong Un.