Seoul: South Korea`s military said on Wednesday it had arrested a Marine private for allegedly assisting an alcohol-fuelled shooting spree by a colleague that left four troops dead and one more injured.
The private is suspected of helping a 19-year-old Marine corporal steal ammunition from a weapons storage room before the latter opened fire at a barracks near the tense sea border with North Korea.
"It appears that neither adjusted well to military life and they were close to each other," the investigator, Navy Commander Kim Young-Soo, told reporters, referring to the private, surnamed Jung, and the corporal, surnamed Kim.
Kim himself has been hospitalised after trying to commit suicide by detonating a hand grenade in Monday`s incident at Gangwha island west of Seoul. His condition is not life-threatening but he can speak little due to injuries.
Jung admitted he and Corporal Kim had hatched a plan to kill colleagues and desert the military but denied involvement in the actual shooting, according to Commander Kim. The four troops killed and one who was injured were all Marines.
The military has said the corporal likely took a K-2 rifle, bullets and the grenade from a weapons storage room that was left open and unattended.
"There are many conflicts in the claims by the two...we are investigating how much he (Jung) was involved and if there were other accomplices," said Commander Kim.
In written comments from his hospital bed, the corporal told investigators on Tuesday that bullying led him to plot the rampage. He complained that neither his superiors nor his juniors respected his rank.
Military psychological tests conducted about a year ago found Kim to be mentally unstable and to have difficulty coping with service life, investigators have said.
Kim had also been drinking before the shooting.
The elite Marine Corps is charged with guarding frontline islands in the Yellow Sea near the disputed border with the North.
But Monday`s incident -- the third in six years -- raised questions about standards of discipline in the South`s largely conscript 650,000-strong military.
Able-bodied South Korean men must undergo at least two years` military service and some complain of abuse and harassment.
Eight soldiers were killed and two seriously injured in 2005 when a soldier threw a grenade and sprayed bullets over sleeping colleagues at a frontline guard post north of Seoul.
The attacker alleged senior colleagues had bullied him.
In 2008, an Army private struggling to adapt to military life threw a grenade at colleagues who were asleep, injuring five.
The Marine Corps on Wednesday held a joint funeral for the four victims and its commander, Lt Gen Yoo Nak-Jun, apologised to their families for his failure to protect them.
"We will try to make sure our soldiers never again hurt each other," Yoo said in his eulogy.
In another development an ex-Marine who served in the same unit from 2006-2007 was awarded state compensation on Wednesday for mental stress and physical injuries caused by bullying, Yonhap news agency reported.
The claimant said he had been constantly beaten by superiors for being introverted and inactive. Seoul`s High Court ruled that "beating was rampant" in the unit, Yonhap said.