North Korea has stationed an artillery battery on the island of Gal-do, South Korean media reported Wednesday, citing South Korean military sources.

According to South Korean military authorities, the Korean People’s Army of the DPRK has positioned a 122mm multiple rocket launcher (MRL) battery on the small island of Gal-do in the Yellow Sea (known in Korea as the West Sea). The island, about half a kilometer long, is located about 2.5 kilometers north of the Northern Limit Line, the maritime boundary between North and South Korean waters, and about 4.5 kilometers from the South Korean island of Yeonpyeong.