CBC News reports say that naval vessels from the Republic of Korea (ROK - the southern Korea) and the Democratic People's Republic of Korea (DPRK - the northern nation) engaged in a brief gun battle yesterday, just before noon local time. The South Korean military says that DPRK patrol boats crossed a disputed nautical demarcation line off the west coast of the peninsula, in the Yellow Sea, about 220 kilometres from Inchon. ROK naval forces responded, firing a warning shot, which led the North Koreans to fire back. Apparently, the South Koreans then retaliated with enough force to set at least one of the DPRK vessels on fire, after which the North Koreans retreated back into their own waters. A South Korean broadcaster claims one North Korean officer was killed and three sailors were wounded. The entire firefight is supposed to have lasted just a couple of minutes.
The battle occurred a week before President Obama is due to visit Asia, including a stop in South Korea, and while the South Koreans are still trying to figure out if this was a deliberate provocation on the part of the Communists, there may be another reason behind the incident: AFP says that the North Koreans entered the disputed waters because they were trying to stop Chinese boats illegally working the crab-fishing grounds in the area. No word if any Somali pirates - er, eco-defenders - were involved.
Map below shows the area where the incident occurred, near the island of Daecheong (#2 on the map). Dotted line indicates the Northern Line Limit, the disputed nautical demarcation between the two Koreas.