China Saturday established the East China Sea Air Defence Identification Zone and announced aircraft identification rules for entering the area.
According to a statement issued by China's defence ministry, aircraft flying in the demarcated zone must abide by these rules or "the armed forces will adopt defensive emergency measures to respond to aircraft that do not cooperate in the identification or refuse to follow the instructions".
Aircraft flying in the zone "should report the flight plans to the Ministry of Foreign Affairs of the People's Republic of China or the Civil Aviation Administration of China", Xinhua quoted the statement as saying.
Aircraft should "maintain the two-way radio communications, and respond in a timely and accurate manner to the identification inquiries from the administrative organ of the zone or the unit authorised by the organ", the statement said.
The statement added that aircraft must clearly mark their nationalities and the logo of their registration identification in accordance with related international treaties.
According to BBC, the demarcated air defence identification zone covers the controversial islands that are also claimed by Japan.
The islands are called Diaoyu in China and Senkaku in Japan. The row over the islands, which are presently controlled by Japan, has left ties between Tokyo and Beijing highly tense.
Relations between Japan and China have soured since the Japanese government said it would "purchase" part of the Diaoyu Islands in the East China Sea in 2012. China insists that the islands are part of its inherent territory.
The islands, which are also claimed by Taiwan, potentially contain oil deposits.
"Setting up such airspace unilaterally escalates the situations surrounding Senkaku islands and has danger of leading to an unexpected situation," BBC quoted Japan's Foreign Ministry as saying in a statement.
Taiwan also expressed regret at the move and promised that the military would take measure to protect national security, the BBC report said.
Chinese military expert Meng Xiangqing said a country has the right to decide on its own whether or how to set up such zones, without getting permission from other countries, if the move does not violate international laws, breach other countries' territorial sovereignty or affect the freedom of flight.
Another expert Yin Zhuo said China's establishment of the zone is based on the need to tackle a more complex security environment, and the move is a justified act to maintain the sovereignty and security of the country's territory and airspace.
People's Liberation Army (PLA) Air Force conducted its first air patrol after the establishment of the air defence identification zone.
Shen Jinke, spokesman for the PLA Air Force, said two large scouts carried out the patrol mission, with early warning aircraft and fighters providing support and cover.
"The patrol is in line with international common practices, and the normal flight of international flights will not be affected," Shen said.
Shen said the Chinese armed forces are capable of effective control over the zone, and will take measures to deal with air threats to protect the security of the country's airspace.
Meanwhile, China's Defence Ministry spokesman Yang Yujun Saturday said the government has followed common international practices in the establishment of the zone, with aims of protecting its state sovereignty and territorial and airspace security, and maintaining flying orders. It is a necessary measure in China's exercise of self-defence rights.
It has no particular target and will not affect the freedom of flight in relevant airspace, the spokesman added.
