According to Huanqiu, on the morning of December 13, 2012, a Chinese maritime surveillance airplane entered into the territorial air space of the Diaoyu Islands (Senkaku Islands in Japan). “This was another significant step forward this year to reinforce the safeguarding of our sovereignty over the Diaoyu Islands. … The Japanese air force responded with eight F-15 fighters and an Early Warning and Control aircraft (AWACS) to intercept the Chinese aircraft." The Huanqiu article stated that Japan no longer has actual control of the Senkaku Islands and that the dispute has now entered a new stage.
Source: Huanqiu, December 14, 2012