South Korea deployed six coast guard and naval vessels after a suspected Chinese fishing boat sank near Yeonpyeong Island in the Yellow Sea on 9 September, according to the Incheon Coast Guard.
The South Korean Navy's Second Fleet alerted the coast guard at about 06:15 that a vessel was sinking around 3.4 nautical miles, or 6.3 km, east of the island in Ongjin County, Incheon.
The wooden vessel was estimated to be about 15 metres long and 3 metres wide. It sank roughly 0.9 nautical miles south of the Northern Limit Line, with most of its hull submerged.
Two coast guard patrol vessels and four South Korean Navy ships were deployed. A coast guard team boarded and searched the vessel, while crews used thermal imaging equipment to sweep the surrounding waters. No people were found aboard and no casualties or marine pollution had been confirmed.
The number of people originally on the vessel remained unknown. Authorities issued navigation safety broadcasts and asked nearby vessels to assist through NAVTEX and the Gyeongin Coastal Vessel Traffic Service.
Chinese authorities were also notified. The search was widened at 11:30 from the immediate wreck area, while authorities monitored whether the vessel could drift as the tide rose.
The vessel was suspected to be Chinese because it sank in an area where Chinese fishing boats were concentrated. Investigators considered it possible that the crew had transferred to another nearby fishing vessel before the sinking. The cause of the sinking remained unknown.