Eight F-15 fighters took to the skies from Japan on Thursday in response to an intrusion into their airspace by a Chinese surveillance plane flying near the disputed Diaoyu Islands. The fighters, launched by the Japanese government were joined by a launch of an E-2C "Hawkeye" observation aircraft from Okinawa.

The Chinese aircraft is the first ever incursion into Japanese airspace according to Japanese officials. Japan’s Chief Secretary Osamu Fujimura condemned the incursion and stated, “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 for three days in a row, as of today, despite our repeated warnings.” Fujimura summoned the Chinese Ambassador to Tokyo after filing an official complaint.

China however, claims the islands as their own and said that the flyover was completely normal. Chinese Foreign Ministry Spokesperson Hong Lei issued a statement in connection with the incident. “The Diaoyu Islands and affiliated islands have been part of China’s territory since antiquity,” said Hong. “China’s surveillance plane flying in airspace over the Diaoyu Islands is completely normal. China calls on Japan to halt illegal activities in waters around Diaoyu islands and airspace.”

Japan bought the uninhabited islands on September 11,2012, they were purchased from a private landowner, the Kurihara family for 2.05 billion Yen. Prior to that time, the Japanese government leased the islands from the family for 25 million Yen a year, this began in 2002. The Chinese claim to have discovered the islands in the 14th century, but the Japanese have controlled the islands from 1895 until Japan’s surrender in 1945.

In a 1997 fishing agreement the islands were officially excluded from China’s exclusive economic zone, but in a letter of intent, Japan said that they would not prevent Chinese fishing boats from fishing in the area. Some in China argue that the agreement constitutes a waiver of Japan’s exclusive fishing rights.

The United States Senate returned control of the islands to Japan in 1972. It was then that both Taiwan and China both officially declared ownership of the islands.