The South Korean government recently initiated an investigation into steel structures built by China near Ieodo, a submerged rock in the Yellow Sea, within the Korea-China Provisional Measures Zone (PMZ). However, Chinese authorities strongly opposed the operation, leading to a tense standoff between the coast guards of both nations.
On Tuesday, government sources revealed that the Onnuri—a 1,422-ton research vessel from the Korea Maritime Institute—was dispatched on February 26 to inspect the unauthorized Chinese installations.
Before the operation, the South Korean government coordinated with its Coast Guard and other key agencies to ensure a smooth mission.
As the Onnuri approached the structures within about 1 kilometer, Chinese Coast Guard personnel and civilians aboard three inflatable boats intercepted the vessel, blocking the deployment of inspection equipment. In response, the South Korean Coast Guard swiftly sent a ship to the area, resulting in a tense two-hour standoff with Chinese authorities.
During the confrontation, Chinese officials insisted the structures were part of a fish farm and demanded that the South Korean vessel leave the area. In response, South Korean authorities maintained that they were conducting a legitimate investigation in line with international law.
Reports indicate that while some Chinese civilians were carrying utility knives, these weapons were not used during the encounter.
The South Korea-China Temporary Measures Zone (PMZ) in the Yellow Sea overlaps both nations’ exclusive economic zones (EEZ). Both countries jointly manage fishery resources in this zone and allow their fishing vessels to operate together. Activities other than navigation and fishing are prohibited.
Recently, however, China has begun installing large mobile steel frame structures in the area, each several dozen meters in diameter and height. This has sparked concerns that these installations could be part of an effort by China to establish a territorial claim in the disputed waters.
Intelligence reports suggest China installed two such structures between April and May last year and added another earlier this year. Chinese officials have maintained that these structures are intended for aquaculture purposes.
South Korean authorities, who have been closely monitoring the situation, attempted a field investigation but were thwarted by China’s opposition. The South Korean government has stated it is actively addressing the issue, including the recent incident, through diplomatic channels with Beijing.