|South Korea stations hundreds of marines on front-line islands within easy striking distance of North Korea [Reuters]
A corporal in South Korea's marine corps has killed four fellow marines and injured another in a shooting rampage at an island base near the country's border with North Korea, according to a military spokesman.
The corporal, identified by his surname Kim, opened fire in the barracks on Monday morning, killing three fellow marines at the scene, Colonel Kim Tae-eun, the marine corps spokesman, told Al Jazeera.
The fourth marine died while being transported via helicopter to a military hospital in Gimpo, a suburb located west of Seoul, the capital, the spokesman said.
The corporal, was taken into custody on Ganghwa island, located 70km west of Seoul, near the border and is currently being treated for injuries obtained from hurling a hand grenade in an attempted suicide, Kim said.
He said an investigation team has been launched to probe the corporal's motive for the killing spree.
Monday's shooting is the worst to happen in South Korean military since 2005, when a soldier killed eight colleagues and wounded several others after tossing a hand grenade and opening fire at a front-line army unit.
The soldier later explained his motive as rage against superiors who verbally assaulted him.
The 2005 incident raised questions about the level of discipline in South Korea's 650,000-strong military.
Two-year military service is mandatory for all able-bodied South Korean men, under a conscription system aimed at deterring aggression from North Korea.
The two Koreas technically remain in a state of war after the devastating 1950-1953 Korean War that ended in an armistice not a peace treaty.
South Korea stations hundreds of marines on front-line islands within easy striking distance of North Korea.
Last year North Korea shelled Yeonpyeong island, killing two civilians and two marines. Tension has taken a toll on South Korea's marines, who would take the brunt of any North Korean attack.
The South Korean military has beefed up marines' combat readiness on a cluster of bases in the Yellow Sea and increased high-tech weapons systems on the islands facing the North.