South Korean troops were engaged Sunday in a fierce gun battle near an elementary school with a runaway soldier who had shot and killed five members of his unit on the border with North Korea.

South Korean troops were engaged Sunday in a fierce gun battle near an elementary school with a runaway soldier who had shot and killed five members of his unit on the border with North Korea.

The 23-year-old army sergeant, surnamed Lim, had opened fire on other South Korean soldiers at a guard post on the eastern section of the heavily guarded frontier Saturday night.

The shooting spree left five dead and seven wounded -- and triggered a massive manhunt after Lee fled the scene armed with a K-2 assault rifle and a stash of ammunition.

A defence ministry spokesman said Lim had been tracked and cornered just before 2:30 pm (0530 GMT) at a location 10 kilometers (six miles) from the border.

"He shot at the pursuing troops and they returned fire," the spokesman said, adding that one officer had been wounded in the arm.

"The situation is still ongoing," he said.

Kim So-Rae, a college student who lives in the area, said she had heard at least three separate exchanges of gunfire.

"There are helicopters flying overhead," Kim told YTN television by telephone.

"We haven't been told anything yet, so we're not evacuating. It's pretty scary."

According to the military, Lim was due to be discharged in the next few months after completing his compulsory military service.

All those killed or wounded in Saturday's incident were members of Lim's own unit of the 22nd infantry division in the eastern province of Gangwon.
The army issued its highest state of alert in nearby areas during the search for Lim, which had involved thousands of soldiers and police who set up roadblocks and inspected vehicles.

Special commandos and army helicopters were also brought in to speed up the operation, while local residents were warned to stay indoors.

Lim had difficulty adapting to the military, and past psychological evaluations had advised senior officers to pay him special attention, a defence ministry official who wished to remain anonymous told AFP.

This is not the first time the 22nd infantry has been involved in such an incident.

In 1984 a private belonging to the same division opened fire and threw a grenade at fellow soldiers in their barracks, killing 15.

The soldier, Cho Jun-Hee, then crossed the border to defect to the North, a move which Pyongyang's state media later confirmed.