Japan scrambles jets in dispute with China over islands BEIJING -- Japan scrambled F-15 fighter jets Thursday in response to a Chinese surveillance plane that flew over contested islands in the East China Sea, ratcheting up a dispute that is becoming increasingly worrisome to the international community. By the time the fighters from Okinawa reached the area, the plane belonging to the Chinese Oceanic Administration had flown away and the incident ended without a confrontation. Nonetheless, it set nerves on edge around the region. Japan's Defense Ministry said it was the first time a Chinese plane had intruded into airspace the Japanese have claimed since at least 1958, although Chinese vessels have frequently been darting into the waters near the islands, known as Senkaku in Japanese and Diaoyu in Chinese. Chief Cabinet secretary Osamu Fujimura said Japan had lodged an official protest and summoned the Chinese ambassador in Tokyo. "It is extremely deplorable that China's official airplane conducted an airspace invasion of Japan's territory today, on top of their intrusion of territorial waters," he said in a statement. The sparring over the uninhabited islands in recent months has become increasingly alarming, with nationalistic fervor rising in the midst of political transitions in both countries. The Chinese Communist Party's new general secretary, Xi Jinping, installed just a month ago, has been trying to prove himself a staunch defender of Chinese sovereignty. In campaigning ahead of Japan's general election on Sunday, opposition leader and former Prime Minister Shinzo Abe has been talking tough about China in hopes of getting his old job back. He has called for an amendment to Japan's pacifist constitution that would expand the nation's Self-Defense Forces. "Nationalism is a tool that many Asian leaders have abused for their political purposes," warned Lee Chung-min, a professor of international relations at Yonsei University in Seoul, speaking this week a security conference in the South Korean capital. For their part, Chinese officials defended what they said was their right to fly the surveillance plane into the area. I want to stress that these activities are completely normal. The Diaoyu and its affiliated islands are China's inherent territory since ancient times," Chinese Foreign Ministry spokesman Hong Lei said in Beijing. The Chinese plane was reported by Tokyo to have flown nine miles south of the largest island in the chain, Uotsuri Jima. The Japanese Defense Ministry said there had only been two other violations of the country's airspace since it began keeping records in 1958, one by a Soviet plane and another from Taiwan. An intrusion by an airplane is potentially far more dangerous than one by a ship because international law gives a country the right to expel an unauthorized aircraft by force. Also, the incident occurred on a sensitive date on the Chinese calendar, marking the 75th anniversary of the start of a massacre by Japanese troops who had occupied the Chinese city of Nanjing in the lead-up to World War II. Memorial services were being held Thursday in the city, previously known as Nanking, for hundreds of thousands of victims of the massacre. Syrian leader may be losing control, Russian official says Britain's Conservatives to propose legalizing same-sex marriage Bosnian Serb general found guilty of genocide, sentenced to life