South Korean Defense Minister Jeong Kyeong-doo on Wednesday strongly reprimanded the military for its failure to detect a North Korean boat that crossed the de facto maritime border and reached a coastal city in the South.

The boat carrying four North Koreans was found along the breakwater in Samcheok Port in Gangwon Province at 6:50 a.m. Saturday.

The small wooden boat had moved at least 130 kilometers from the Northern Limit Line to reach the port city in four days, but the military and police became aware of the incident only after a South Korean civilian reported it to the authorities.

During a conference of top commanders, Jeong vowed to take measures to tighten maritime vigilance and prevent the recurrence of such incidents.

“Even if we do well in 100 tasks, we cannot gain the public’s trust if we fail in one security operation,” Jeong said. “We should identify problems in management of the forces and take necessary measures in a fast and timely manner.”

Jeong also said the military should never forget the importance of its duty to protect people’s lives and safety, adding that he would hold liable those responsible for the incident.

Top military commanders, including the chairman of the Joint Chiefs of Staff and heads of the Army, Air Force and Navy, were present at the meeting.

The incident has raised alarm over the military’s surveillance capability.

According to the government’s investigation, the four North Koreans departed from North Hamgyong Province on June 9 and joined North Korean fishing boats near the Northern Limit Line on June 10.

They pretended that their vessel was a fishing boat for two days and crossed the de facto maritime border at around 9 p.m. on June 12.

After drifting around the South Korean island of Ulleungdo on June 13 for some time, they sailed to reach the closest land and arrived at the seawall of the Samcheok Port on June 15.

The South Korean resident asked where they were from and called the police when they replied that they were from North Korea. The North Koreans also asked the man if they could borrow a cellphone to call an aunt who lives in Seoul.

The Defense Ministry said the four North Koreans have been identified as civilians. Two of them returned to the North via Panmunjom on Tuesday at their request.

A joint investigation team is conducting further interrogation of the remaining two who expressed a desire to stay in South Korea. If the investigation is completed without turning up irregularities, they are expected to take the steps needed to defect to South Korea.

“Two of them testified that they had left North Korea with the intention to defect to the South,” an official from the ministry said.

According to the ministry, imagery from Intelligence Video Surveillance cameras showed the boat was captured twice, for one second each time. But the operator had thought it was a domestic vessel and did not take action.

Normal security operations -- using patrol planes, maritime radars and naval vessels -- were conducted, but the ministry had initially said they were not able to identify the boat as it was small in size and made of wood.

The 1.8-ton wooden boat is 10 meters in length, 2.5 meters in width and 1.3 meters in height, with a 28-horsepower engine.

(herim@heraldcorp.com)