SEOUL, Feb. 7 -- The weight of a newly launched satellite of the Democratic People's Republic of Korea (DPRK) was estimated to have doubled that of its predecessor, indicating an advancement in ballistic missile technology, South Korea's spy agency said Sunday.

The DPRK announced a successful launch of a Kwangmyongsong-4 Earth observation satellite into space aboard a Kwangmyongsong rocket, which Seoul sees as a long-range ballistic missile.

The National Intelligence Service (NIS) reported on the launch to the parliamentary intelligence committee, two members of the committee told reporters, according to Yonhap news agency report.

The Kwangmyongsong was estimated to weigh around 200 kilograms, two-fold the weight of its predecessor Kwangmyongsong-3 that was launched by the DPRK in December 2012 into orbit.

The spy agency believed that the newly launched rocket didn't go through an experiment of atmospheric re-entry, a prerequisite for developing an intercontinental ballistic missile (ICBM).

But, the DPRK seemed to have advanced ICBM technologies on rocket stage separation and guided control given the flight time, stage separations and drop zones of the separated stages.

Whether the satellite works normally will take a couple of days to determine, according to the NIS. The rocket's key components were estimated to have been imported mostly from Russia.