A Chinese People’s Liberation Army-Navy Type 815 Dongdiao-class spy ship entered Japanese territorial waters on Wednesday, according to Japan’s defense ministry. The move is the first of its kind since 2004, when a Chinese nuclear submarine entered Japan’s 12 nautical mile territorial sea near Sakishima Islands, in Okinawa prefecture.

According to a Kyodo News report of the Wednesday’s incident, a “naval intelligence ship was spotted around 3:30 a.m. west of Kuchinoerabu Island.” The ship “left the territorial waters just a few hours later.” (Japan’s Defense Ministry notes that the ship left around 5 a.m.) Kuchinoerabu Island is approximately 38 nautical miles from the Japanese island of Kyushu, which is one of Japan’s four main islands along with Honshu, Hokkaido, and Shikoku.

Japan and China have a territorial dispute in the East China Sea over the sovereignty of the Senkaku/Diaoyu Islands, which are administered by Japan, but claimed by China. Wednesday’s incident did not take place in the vicinity of these islands. (The Senkakus are approximately 450 nautical miles from Kuchinoerabu Island.) Last week, however, for the first time ever, a Chinese warship entered the contiguous zone of the Senkaku/Diaoyu Islands, in a move that highlights growing tensions between the two countries in the East China Sea.

http://thediplomat.com/2016/06/for-first-time-since-2004-chinese-warship-enters-japanese-territorial-sea-in-east-china-sea/