Updated

The military searched Sunday for an armed South Korean soldier who fled after killing five of his comrades and wounding seven at an outpost near the North Korean border.

The sergeant, identified only by his surname, Yim, opened fire Saturday night with his standard issue K2 assault rifle at an outpost in Gangwon province, east of Seoul, according to a Defense Ministry spokesman. He spoke on condition of anonymity because of department rules.

Yim, who was scheduled to be discharged from the military in September, fled with his weapon, but it wasn't clear how much live ammunition he had, the official said.

Defense official Kim Min-seok said Sunday at a televised briefing that all the wounded were expected to survive, although two were injured seriously. He said search operations were underway to quickly find Yim, without elaborating.

Park Cheol-yong, the head of Madal village, near the army division where the gunfire took place, said he warned villagers to stay in their houses. Park Jin-soo, a pastor at a church in the village, said that Sunday services would take place as usual despite the tension over the missing soldier and the shooting.

Thousands of troops from the rival Koreas are squared off along the world's most heavily armed border.

There was no indication that North Korea was involved. But tensions between the two countries have been high recently, with North Korea staging a series of missile and artillery drills and threatening South Korea's leader. The Koreas have also traded fire along their disputed maritime border in the Yellow Sea. South Korea has repeatedly vowed to respond with strength if provoked by the North.

Shootings happen occasionally at the border.

In 2011, a 19-year-old marine corporal went on a shooting rampage at a Gwanghwa Island base, just south of the maritime border with North Korea. Military investigators later said that corporal was angry about being shunned and slighted and showed signs of mental illness before the shooting.

In 2005, a soldier tossed a hand grenade and opened fire at a front-line army unit in a rampage that killed eight colleagues and injured several others. Pfc. Kim Dong-min told investigators he was enraged at superiors who verbally abused him.

All able-bodied South Korean men must serve about two years in the military under a conscription system aimed at countering aggression from North Korea.

The Korean Peninsula is still technically in a state of war as the 1950-53 Korean War ended with an armistice, not a peace treaty. About 28,500 U.S. soldiers are stationed in South Korea as a deterrent against North Korean aggression.