China's "coercive" behaviour in waters around islands at the centre of a bitter dispute with Japan is dangerous and could trigger an incident, Tokyo said in a new defence paper
At a cabinet meeting, the Japanese prime minister, Shinzo Abe, and his ministers adopted the defence white paper, the first annual report on Japan's defence capabilities and regional security since the islands dispute flared anew last year.
Tokyo took three of the five Senkaku islands out of private ownership in September. Beijing lays claim to the islands, and calls them the Diaoyus.
"China ... has taken action described as coercive, which includes risky behaviour," the 450-page report said.
"China's activities include its intrusion into Japan's territorial waters, its violation of Japan's territorial airspace and even dangerous actions that could cause a contingency," it said.
In particular, the paper said a Chinese frigate locked weapons-targeting radar on a Japanese destroyer in January - a claim Beijing has denied.
"These acts are extremely regrettable and China should accept and stick to the international norms," it said.
Japan is currently considering chaning its pacifist constitution and the role of its Defence Force, and acquiring the capability to attack enemy targets.
Chinese and Japanese ships have for months traded warnings over intrusions into what both governments regard as their sovereign areas around the islands, which are strategically sited and rich in resources.
Chinese ships have regularly sailed into the 12 nautical mile territorial waters of the islands, where they are confronted by Japan's well-equipped coastguard.