According to the South Korean Government, North Korea fired weapons into South Korea territorial waters and South Korea returned fire on the North Koreans. The shots took place in western disputed maritime territory, where earlier this week, North Korea announced they would hold live-fire drills.
The two Koreas have an armistice agreement from 1953 which seeks to prevent any military movement between the two nations, although this is not the first time in recent history where there has been an exchange of fire. The geographic region where the gunfire was exchanged has been an area of contention for many years. In 2010, the North Koreans killed four South Koreans in the same area.
The North Koreans had said they were be live firing artillery in 7 regions. South Koreans made it explicitly clear that if any of that artillery passed into their territory, they would respond accordingly. Apparently, that is what has happened in this case. According to the AFP News Agency military spokesman, “Some of the shells fired by North Korea dropped in our area and our side responded with fire.” According to sources on the ground, local citizens were evacuated and moved to shelters in precaution of the act.