Wi Seong-rak, director of the National Security Office, told reporters at a Blue House briefing on the afternoon of the 11th: "Our government condemns attacks on civilian ships such as the Namu as unjustifiable and unacceptable."
He said authorities will continue their probe to identify the attacker, determine the exact type of aerial object involved, and establish its physical size. "We will consider appropriate response measures based on those findings," he added.
Earlier, the foreign ministry — citing the on-site findings of the government's joint investigation team — said that on the 4th at 3:30 p.m. local time, two unidentified aerial objects struck the HMM Namu's stern, hitting the outer hull of the port-side ballast tank twice at roughly one-minute intervals.
Investigators reviewed CCTV footage, interviewed the ship's captain and carried out a detailed on-site inspection.
Wi explained: "Two unidentified aerial objects struck the ship's stern outer hull twice about one minute apart. The impacts produced flames and smoke accompanied by vibrations."
He said the damage was located about 1 to 1.5 meters above the waterline, and that the pattern of blast-pressure damage and a hemispherical penetration shape make a mine or torpedo explosion appear unlikely.
Still, the Blue House emphasized caution in naming a perpetrator.
A senior Blue House official told reporters the government is working to determine the cause without attributing the attack to any party. "It's difficult to pre-judge or promise a specific response in advance," the official said. "We will act at an appropriate level once we reach a judgment."
When asked why the government had assessed a low likelihood of an external strike on the 6th, the official said investigators at that time had not confirmed any hull breaches and had received reports of no flooding or listing. "Although the possibility of an external impact existed, we could not make a definitive judgment then," the official said.
"That earlier assessment was not incorrect," the official added, "but further investigation later increased recognition of a possible strike."
Wi said the government will continue communicating with relevant countries to prevent similar incidents and will step up efforts to protect South Korean seafarers and vessels operating in nearby waters.
He also said South Korea will continue participating in international efforts to ensure the safety and free passage of all ships.
