
A spokesman for Japan's Coast Guard said it has deployed 10 new 1,500-ton vessels and two helicopters carriers at its branch in Nahacity on the island of Okinawa, 1,600 kilometres south-west of Tokyo.
Chinese coast guard vessels have more often approached the Japanese-administered Senkaku Islands since Japan bought three of the islets from a private owner in September 2012.
The incidents have aggravated Japan's relations with China, which claims the uninhabited islets, as does Taiwan, under the names of Diaoyu and Tiaoyutai, respectively.
A week ago, Japan also stationed a unit of 160 ground troops on Yanaguni Island, 150 kilometres south of the disputed islets, to monitor vessels and aircraft in the area.
- DPA