BEIJING/WASHINGTON - China sent several fighter jets and an early warning aircraft into its new air defence zone over the East China Sea, state news agency Xinhua said on Friday, raising the stakes in a standoff with the United States, Japan and South Korea.
Japan and South Korea also flew military aircraft through the zone, the two nations said on Thursday, while Washington sent two unarmed B-52 bombers into the airspace earlier this week in a sign of support for its ally Japan. None of those aircraft informed Beijing.
China last week announced that foreign aircraft passing through its new air defence zone - including passenger planes - would have to identify themselves to Chinese authorities. The zone includes the skies over islands at the heart of a territorial dispute between Japan and China.
The Chinese patrol mission, conducted on Thursday, was "a defensive measure and in line with international common practices", Xinhua cited air force spokesman Shen Jinke as saying.
The aircraft, including Russian-designed Su-30 fighter jets, conducted routine patrols and monitored targets in the zone, Shen said.
"China's air force is on high alert and will take measures to deal with diverse air threats to firmly protect the security of the country's airspace," he said.
However, Defence Ministry spokesman Yang Yujun said it was"incorrect" to suggest China would shoot down aircraft which entered the zone without first identifying themselves. He did not elaborate.
Japan's Chief Cabinet Secretary Yoshihide Suga said on Friday he did not know if Chinese planes were in the zone but added there was no change to Tokyo's sense of alertness.
Ties between China and Japan have been strained for months by the dispute over the islands in the East China Sea, called the Diaoyu by China and the Senkaku by Japan.
Washington does not take a position on the sovereignty of the islands but recognises Tokyo's administrative control and says the US-Japan security pact applies to them.