"On February 12, it was confirmed that a Chinese Navy Shupang-class survey ship sailed through Japan’s territorial waters near Yakushima Island. This is the 10th time, the first since December last year, that we announce Chinese Naval vessel’s entry into Japan’s territorial waters," the ministry tweeted.
Such naval activities carried out by China are of national security concern, the ministry added.
Japanese media reported, citing the defense ministry, that Tokyo expressed concern over the vessel's actions to Beijing through diplomatic channels.