South and North Korean naval vessels exchanged fire in the West Sea, Tuesday, after the latter violated the Northern Limit Line (NLL), the de facto maritime border between the two Koreas, said the Joint Chiefs of Staff (JCS) in a statement.
The clash came three days after the North ramped up its peace offensive by sending three top aides of Kim Jong-un ― Hwang Pyong-so, Choe Ryong-hae, and Kim Yang-gon ― to the South.
According to the JCS, Pyongyang's patrol boat crossed the NLL some 900 meters into the South's territorial waters at 9:50 a.m., and returned to the North at 10 a.m. after the incident.
"Following the violation, Seoul's guided-missile patrol boat issued warning messages and fired a warning shot to force the vessel from the North to retreat," said the JCS in a statement. "The North Korean boat fired back rather than backing down, which caused us to fire again. Then the ship retreated."
The South fired about 90 shots in total toward the vessel from the North, according to a JCS official.
The official noted, "Our forces did not sustain any damage. It appears that the North's boat was not damaged either." He added that neither side had aimed with the intention of causing damage. According to the Yonhap News Agency, ten of the shots fired from the South Korean vessel were from 76 millimeter guns.
Despite this, it is a rare for the two Koreas to exchange fire when a Pyongyang vessel crosses into the NLL. In most cases, boats from the Stalinist state retreat without firing back after warning shots are issued from the South.
Tuesday's trading of fire between the two vessels was the first since the "Battle of Daecheong" that occurred in 2009.
Defense Minister Han Min-koo added that, "The two Koreas have engaged in a gunfight." Han made the remarks during a parliamentary audit of the Ministry of National Defense.
The JCS said that the South has maintained full readiness while closely watching movements by the North Korean military.
"No other extraordinary movements were detected at the border region when the North's vessels intruded into our side," it said.
The NLL was drawn up by the U.S.-led United Nations Command at the end of the 1950-53 Korean War. The reclusive state does not recognize the border and the area has been the location of several bloody clashes between the two sides.
Follow Jun Ji-hye on Twitter @TheKopJihye