South Korea's intelligence agency told lawmajers Thursday that North Korea is focused on developing a middle stage missile for its goal to build an intercontinental ballistic missile.

During a meeting of the National Assembly's Intelligence Committee, the National Intelligence Service(NIS) said the North's KN-17 antiship missile has a range of five thousand kilometers, enabled by a new type of liquid propulsion engine.

Liberty Korea Party lawmaker Yi Wan-young, a member of the intelligence committee, passed on that assessment. 

Separately, the NIS also told the Assembly that six South Koreans are currently detained in North Korea and the figure rises to ten if ethnic Koreans of foreign nationality are counted. 

The NIS said that of the six South Koreans, three are pastors who visited the North for missionary activities.