Japan is incensed by an article in China's state-run People's Daily claiming Okinawa and its connected island chain rightly belong to China.
Japan's Chief Cabinet Secretary Yoshihide Suga on Wednesday said Tokyo lodged a strong protest, according to Kyodo News. It is rare for such a senior Japanese official to issue a protest over a Chinese newspaper article.
Suga called the article "injudicious" and insisted Japan's sovereignty over Okinawa is both historically evident and legitimate under international laws.
China has drawn the line, saying the piece was the view of one academic and does not represent Beijing's official position. Chinese Foreign Ministry spokeswoman Hua Chunying said the Okinawa and Ryukyu island chains have been a subject of interest for scholars for a long time.
But she stressed that the Diaoyu or Senkaku Islands, administered by Tokyo and claimed by Beijing, are a different matter and do belong to China.