The Democratic People's Republic of Korea (DPRK) forces returned fire in the waters near the Military Demarcation Line early Monday after a South Korean warship opened "warning fire," the official Korean Central News Agency (KCNA) reported.An escort ship of the South Korean navy opened "warning fire" with the excuse of controlling a ship in the waters 20 km northwest of Paekryong (called Baengnyeong by South Korea) Island, at around 3:50 a.m. local time Monday (1850 GMT, Sunday), the KCNA quoted a spokesman for the General Staff of the Korean People's Army of DPRK as saying.The DPRK coastal defense units on the western front took a countermeasure to expel the South Korean warship by firing 10 shells of multiple rocket launchers toward the waters, as "threatening and warning fires," the spokesman said in a statement.On the South Korean side, the Joint Chiefs of Staff said Monday that a DPRK merchant vessel violated the Northern Limit Line in waters near the front-line island of Baengnyeong at 3:42 a.m. local time (1842 GMT, Sunday) and that South Korea's navy issued warning messages and fired warning shots.The Northern Limit Line is a disputed maritime demarcation line between the DPRK and South Korea, which the DPRK has never officially recognized.The Democratic People's Republic of Korea (DPRK) forces returned fire in the waters near the Military Demarcation Line early Monday after a South Korean warship opened "warning fire," the official Korean Central News Agency (KCNA) reported.An escort ship of the South Korean navy opened "warning fire" with the excuse of controlling a ship in the waters 20 km northwest of Paekryong (called Baengnyeong by South Korea) Island, at around 3:50 a.m. local time Monday (1850 GMT, Sunday), the KCNA quoted a spokesman for the General Staff of the Korean People's Army of DPRK as saying.The DPRK coastal defense units on the western front took a countermeasure to expel the South Korean warship by firing 10 shells of multiple rocket launchers toward the waters, as "threatening and warning fires," the spokesman said in a statement.On the South Korean side, the Joint Chiefs of Staff said Monday that a DPRK merchant vessel violated the Northern Limit Line in waters near the front-line island of Baengnyeong at 3:42 a.m. local time (1842 GMT, Sunday) and that South Korea's navy issued warning messages and fired warning shots.The Northern Limit Line is a disputed maritime demarcation line between the DPRK and South Korea, which the DPRK has never officially recognized.