The Defense Ministry said Wednesday that two Chinese warships steamed through waters between Okinawa Island and Miyako Island on Tuesday night but did not intrude into Japan's territorial waters.
The Chinese vessels did not approach the Senkaku Islands or enter Japan's contiguous zone around the islets in the East China Sea, according to a government official in Tokyo. The islets are administered by Japan but claimed by China.
"If that were the case, the Defense Ministry would be responding, but I haven't been given any such report," the official said.
However, China's official Xinhua news agency reported that a fleet of the Chinese People's Liberation Army Navy on Wednesday morning patrolled the waters around the disputed islets, called Diaoyu by China. Xinhua said the fleet sent to the vicinity consists of vessels from the Nanhai Fleet of China's navy.
The move came on the anniversary of Japan and China signing the Treaty of Shimonoseki in 1895 to end the Sino-Japanese War. Some observers speculated that since China has stressed that the Senkakus were "stolen from China by Japan at the end of the Sino-Japanese War," the latest action could be a way for Beijing to promote its argument internationally.
But some also suggested that Beijing may have sent the warships to the area because Taiwan on Wednesday held its first live-fire military exercise since 2008 to test its ability to fend off an attack from China.