South Korean troops cornered a conscript soldier who killed five comrades near the heavily militarised border with North Korea on Monday, and were trying to negotiate a peaceful end to a manhunt that started two days' earlier with a grenade attack.
The defence ministry said officials were trying to persuade the 22-year-old to surrender in a densely forested area near a small town in Goseong county, a mountainous region on the eastern coast of the peninsula.
Late on Saturday night the soldier threw a grenade and opened fire, killing five members of his unit and wounding seven at a base outpost in Goseong county.
The soldier, surnamed Lim, was described by an official as an "introvert" and said there had been earlier concerns over his psychological health, but he was deemed fit to be deployed to the outpost after passing a test in November.
A massive manhunt saw troops, who had orders to "shoot to kill" if the soldier failed to surrender, exchange gunfire with him on Sunday. A platoon leader was wounded in a gunfight.
"The idea is to capture him, but we are trying to get him to surrender," defence ministry spokesman Kim Min-seok told a briefing. "We are tightening the circle around him."
The soldier was allowed to speak to his father by telephone and officials are working with his parents to try to convince him to turn himself in, Kim said.
Another soldier was wounded on Monday in a friendly fire incident during the pursuit for the rogue soldier, Kim said.
Concerns about new recruits
The military has been criticised before for lax discipline in some units and failure to prevent previous cases where soldiers, suffering personal problems, have shot fellow soldiers.
In a similar incident in 2011, a South Korean marine went on a shooting spree at a base near the tense maritime border with North Korea, killing four fellow soldiers before trying to blow himself up with a hand grenade.
Kim, the defence ministry spokesman, said a large number of conscript soldiers, most of whom are in their early 20s, are classified as "of interest" and are under supervision by the command for concerns over potential disciplinary or mental health issues.
About 800 soldiers of the 22nd Infantry Division that serves the Goseong region, or 9 percent of division force, are under supervision, Kim said. Lim was one of them.
All able-bodied South Korean men serve about two years under a conscription system that makes up a large part of the 600,000 active service troops, and there are concerns that new recruits are softer and find it harder to adapt to military life.
A lockdown was in effect around the search zone, including guard posts along the Demilitarized Zone border, a 4-km (2.5-mile) wide swathe of land serving as a buffer between the two Koreas since the end of the 1950-53 Korean war.
The two Koreas remain technically at war since the conflict ended in a truce not a peace treaty, and the border is regarded as potentially one of the world's most dangerous flashpoints.