Japan urged China on Tuesday to exercise restraint over tensions in the South China Sea after reports that a Vietnamese fishing boat was rammed by a Chinese fishing boat and sunk in disputed waters the previous day.
"It was an extremely dangerous action that could threaten people's lives," Chief Cabinet Secretary Yoshihide Suga told a news conference in Tokyo. "It is important for the countries concerned to refrain from unilateral action that would raise tensions and to handle matters calmly, while observing international law."
Monday's incident was the first reported sinking of a ship since China stationed an oil rig near the Paracel Islands in the South China Sea in early May. Vietnamese and Chinese ships have since collided with each other repeatedly near the islands, which are claimed by both countries but controlled by China.
Saying the reported sinking poses a "serious problem," Japanese Defense Minister Itsunori Onodera told a news conference the same day that facts around the incident "need to be revealed in a steady manner within the international community."
The incident came just days after Chinese fighter jets flew unusually close to Japanese Air and Maritime Self-Defense Force airplanes above the East China Sea, where disputed islands are located.
The defense chief indicated the same day that a code of conduct needs to be considered in multilateral settings to ensure safety in airspace. "If it's difficult to develop a framework between Japan and China, it's important to propose one in multilateral settings," he said.
Ten crew members on the Vietnamese fishing boat that sunk in the South China Sea were rescued by another Vietnamese ship, according to reports.