North Korea has started work to build a facility on an island near the tense western sea border with South Korea, prompting the South Korean military to closely monitor the movements, the South Korean Defense Ministry said Thursday.
"North Korea is doing works in Galdo, about 4.5 kilometers north of (South Korea's) Yeonpyeong Island, and the purpose of the works is yet to be determined," ministry spokesman Kim Min Seok told journalists.
Kim said that the South Korean authorities suspect the facility is for military purposes, given the fact that the island is uninhabited. "The works just got underway, and we are closely watching the area," he added.
Inter-Korean tensions near the western maritime border dangerously escalated in November 2010 when North Korea launched an artillery bombardment into Yeonpyeong Island, killing two marines and two civilians.