Fears grow of clash as Japanese and Chinese ships and planes patrol disputed 'Diaoyu' islands

The move is likely to heighten tensions as relations between the two powers become increasingly strained over the dispute

Part of the disputed Senkaku islands (AP)

China has established an “Air Defence Identification Zone” over a group of islands subject to a territorial dispute with Japan that has strained relations between the two powers for months.

China’s Defence Ministry has threatened “defensive emergency measures” against aircrafts flying over the area in the East China Sea who do not comply with the new rules, in a move that is likely to greatly anger Japan.

The defence zone, which came into effect on Saturday morning, means any aircraft entering the airspace must report flight plans to Chinese authorities, maintain radio contact and reply promptly to identification inquiries.

Although the islands, called Senkaku in Japan and Diaoyu in China, are uninhabited, they are believed to be surrounded by energy-rich waters. The long standing dispute, tensions over which have recently been raised, is also seen as a subject of national pride.

Patrol ships from both countries have been shadowing each other near the islets, raising fears that a confrontation could develop into a clash.

There have also been several incidents involving military aircraft flying close to each other. In October, Chinese military aircraft flew near Japan three days in a row, and Japan scrambled fighter jets each time in response.

In answer to questions about the zone on an official state website, Yang Yujun, a defence ministry spokesman, said China has established the zone “with the aim of safeguarding state sovereignty, territorial land and air security, and maintaining flight order”.

The Japanese Foreign Ministry has so far made no comment on the announcement.