TOKYO • Japan scrambled jets after a fleet of Chinese aircraft flew over a strategically important strait near disputed isles in the East China Sea.

Japan sent out the jets after eight of the Chinese planes crossed back and forth on Sunday over waters between Okinawa's main island and Miyako-jima near Taiwan, the Defence Ministry in Tokyo said in a statement yesterday. Two of the planes may have been fighter jets.

While the Chinese planes did not cross into Japanese airspace, it was the first time that Japan saw Chinese fighter jets in the Miyako Strait, Chief Cabinet Secretary Yoshihide Suga said.

China's navy has often used the Miyako Strait, a key strategic route for the military, as a pathway from eastern China to the Pacific Ocean.

China's Defence Ministry on Sunday said the "routine" drill involving a fleet of 40 aircraft - comprising H-6K bombers, Su-30 fighters and air tankers - was aimed at "testing far sea combat capabilities".

The planes were en route to the Western Pacific for exercises, it said.

Earlier this month, Chinese bombers, fighters and early-warning and aerial-refuelling aircraft flew through the Bashi Channel that separates Taiwan and the Philippines to exercises in the Western Pacific.

The fleet on Sunday performed surveillance, sudden-assault and aerial-refuelling exercises, as well as "routine warning patrols" in China's Air Defence Identification Zone (ADIZ) in the East China Sea, said the Chinese Defence Ministry.

China drew condemnation from Japan and the United States in 2013 when it imposed an ADIZ in the East China Sea, in which aircraft are supposed to identify themselves to the Chinese authorities.

Japanese Prime Minister Shinzo Abe told Parliament that he is looking to improve relations with China, but any unilateral attempts to change the status quo must not be tolerated in the East China Sea, South China Sea or anywhere else.

The display of force by the Chinese military came after Japanese Defence Minister Tomomi Inada said in Washington earlier this month that Tokyo would increase its engagement in the South China Sea through joint training cruises with the US Navy, exercises with regional navies and capacity-building assistance to coastal nations.

Mr Xu Guangyu, senior adviser at the Beijing-based research group the China Arms Control and Disarmament Association, said the size of the Chinese fleet over the weekend was uncommon.

BLOOMBERG, REUTERS