South Korea apologises after failing to spot defector

South Korea's defence chief has dismissed three officers and apologised publicly after his troops failed to spot a North Korean soldier defecting to the south across the heavily guarded border.
No one detected the soldier – even though he scaled barbed wire fences on the South Korean side – until he knocked on the door of frontline South Korean barracks to say he was defecting.
The incident on 2 October raises questions about South Korea's military surveillance capabilities.
The defence minister, Kim Kwan-jin, told a news conference he "deeply" apologised for causing public concern over the defection.
"There were an obvious failure in security operations and faults in situation-reporting systems," Kim said.
Fourteen officers, including five at general level, will be investigated for possible punishment over the incident, ministry spokesman Kim Min-seok said. The ministry dismissed three officers, including a division commander, from their posts on Monday, officials said.
Last week, President Lee Myung-bak ordered stern punishment for those responsible for the security breach.
A ministry statement said border security would be strengthened by deploying more guards and modern surveillance equipment and installing more wire fences.
The Korean peninsula has remained divided along the 2.5-mile-wide (4km) demilitarised zone since the Korean war ended in 1953 with an armistice. There has never been a peace treaty. It is guarded by hundreds of thousands of combat-ready troops on both sides and is strewn with land mines and laced with barbed wire.
About 24,000 North Koreans have defected to South Korea since the end of the war, but defections across the land border are rare, with the vast majority of defectors fleeing through China and south-east Asian nations for the south.
Defections by soldiers are also unusual, although another North Korean soldier defected to South Korea via the land border after killing two officers earlier this month.