(ATTN: ADDS more details in paras 8-9, 11-15, 21, 23-27)
By Oh Seok-min
SEOUL, July 3 (Yonhap) -- The government on Wednesday rejected all suspicions of a cover-up in connection with last month's undetected arrival of a North Korean boat at an east coast port, even though it acknowledged a "grave mistake" in securing the border and reprimanded top military commanders.
The government has been under fire following revelations that the military failed to detect the small wooden boat carrying four North Koreans until it traveled all the way to the port of Samcheok, about 130 kilometers away from the eastern sea border, and a civilian alerted police about it on June 15.
Fueling the criticism were allegations that the military gave an incorrect account of what happened, including saying the boat was found in the "vicinity" of the port, not at the port, sparking widespread suspicions that it tried to cover up the border security failure.
"The investigation into the case found a failure in the military's surveillance operations and a failure in appropriately informing the public of the case," Defense Minister Jeong Kyeong-doo said during a news conference to announce the results of a weekslong investigation into the case.
Calling the security lapse an "unacceptably grave mistake," the ministry relieved the commander of the Army's 8th Corps of his duty, holding him responsible for the failure in his operational area.
The government also rebuked Joint Chiefs of Staff (JCS) Chairman Park Han-ki, and referred Maj. Gen. Lee Gye-cheol, who leads the Army's 23rd Infantry Division, and R. Adm. Kim Myeong-soo, commander of the Navy's First Fleet, to the military's disciplinary committee.
The Army is in charge of coastal operations, and the Navy conducts missions for maritime defense.
According to the government probe, the 1.8-ton wooden boat with a 28-horsepower engine left the North's Hamgyong Province on June 8 and crossed the Northern Limit Line (NLL) unchecked about four days later on June 12.
After moving further south the following two days, the men turned the engine off late on June 14 and stayed overnight at sea until dawn. The boat then began moving to the port and reached the dock at around 6:20 a.m. on June 15.
For the approximately 57 hours that the boat sailed through South Korean territorial waters, neither the military nor the Coast Guard detected it. They sailed a total of 700 kilometers before arriving in the South.
For maritime and coastal security in the East Sea, the Army runs coastal surveillance radar systems as well as thermal observation devices (TODs). The Navy operates vessels at sea and P-3C maritime surveillance aircraft.
According to the probe, Army soldiers in charge of monitoring coastal radar misunderstood what was picked up by their equipment as "a reflective wave," while radars operated by the Navy and the Coast Guard failed to detect the wooden boat.
Though the Army's video monitoring system did capture the wooden boat twice, the soldiers turned out to have pegged the vessel as a South Korean fishing boat, the probe showed. It also found that the thermal observation devices were operated only at night in accordance with the Army's operational manual.
The arrival of the wooden boat was captured by several closed-circuit televisions set up around the port, but officials failed to discern the boat to be a North Korean one, according to the investigation.
"Taken together, surveillance operations failed to carefully discern the small wooden boat captured by radars and the video system, and the military had not effectively managed TODs, leading to loopholes in maritime and coastal surveillance operations," Choi Byung-hwan, first vice minister of the Office for Government Policy Coordination, said.
In order to prevent any recurrence, the government vowed to boost the capabilities of operating surveillance equipment and to replace aging equipment at an early date.
"We will optimize the management of all possible defense capabilities ... and boost the complementary management system among services," Choi said, vowing to improve education and training programs for service persons.
The government, however, dismissed suspicions it tried to conceal or water down the case.
Such allegations have mounted after the JCS said during its first public briefing following the incident on June 17 that the military's overall operations had proceeded "normally" and that the boat was found "in the vicinity of" the port, while stopping short of saying that the boat was actually tied up by the quay.
"The usage of the term was only in consideration of military security circumstances, while neglecting the common notion of the public," Choi said, adding that officers "admitted that it was very inappropriate and naive to say that there were no problems in surveillance operations."
The government, however, refused to say who first gave instructions for the use of such a vague word.
"We failed to make full and precise explanations to the public, as we made a wrongful judgment about the early situations ... We will take a more sincere stance not to have people bear suspicions over such incidents," the defense minister said.
The probe also confirmed that the four North Koreans were all civilians, and no evidence of espionage was found.
All of them first expressed their willingness to defect to the South during the initial probe, but two later changed their mind and were sent home over the land border accordingly on June 18, according to the government.
The remaining two have stayed here as they expressed their desire to defect to the South and have been going through due procedures required for such defectors, the vice minister said.
The incident took place as South Korea has pursued rapprochement with North Korea since last year, including the signing of the inter-Korean military agreement that calls for a series of measures aiming to reduce tensions and build trust.
But some South Koreans, particularly conservatives, have raised concerns over the possible loosening of the country's defense posture, a claim dismissed by the government, which says a firm readiness posture is the bedrock for peace.
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