North Korea is building military facilities on an uninhabited island near the de-facto maritime border in the Yellow Sea.
 
An official of the South Korean Joint Chiefs of Staff (JCS) said Tuesday that the North has been carrying out excavation and foundation work since March on the island of Galdo, located two-and-a-half kilometers north of the Northern Limit Line (NLL).
 
The official said it seems the North recently completed building about five facilities which appear to be bunkers.
 
Military authorities believe that once construction is complete, the North will likely use the site to monitor the South or to deploy artillery.
 
A JCS official said if the North attacks with artillery from the island of Galdo, it would deal a significant blow to South Korean marine units on Yeonpyeong Island and warships operating in nearby waters, noting that Galdo is just four-and-a-half kilometers from Yeonpyeong Island.
 
Military authorities are said to be keeping a close eye on the North and reviewing response strategies to its provocations.
 
As the North conducted live-fire drills near its western maritime border with the South on May 13 and 14, the possibility of provocations against the South is growing.