China today established an air defence zone over disputed islands administered by Japan, a move that can exasperate tensions between the two countries.         Defence Ministry announced the establishment of East China Sea Air Defence Identification Zone which comes into operation from today. It warned that the aircraft flying over the area should seek permission failing which they are liable for action, state-run Xinhua news agency reported.        

The zone includes the airspace within the area enclosed by China's outer limit of the territorial sea, it said specifying boundaries in the East China Sea, where the uninhabited disputed islands called Diaoyu by China and Senkakus by Japan were located.        

If enforced strictly the new Chinese law could spark off major military tensions with Japan, which has been administering the group if islets believed to be rich with minerals and hydro carbons.        

China stepped up its protests over Japanese control from September last year after Tokyo bought the islets from a private Japanese party, which Beijing said amounted to nationalisation of the islands and pressed its fleet of war ships to patrol aggressively with that of Japanese patrols.