TOKYO - The Japanese coast guard says its patrol boats have been pushing back hundreds of North Korean boats trying to poach in fishing grounds rich with squid off Japan’s northern coast.

Coast Guard officials said Tuesday they have forced more than 300 North Korean boats out of Japan’s exclusive economic zone near Yamatotai since May. </s> Japanese air force jet scrambled around 200 times in the three months ending on Thursday compared with 114 times in the year-earlier period, he said. Detailed figures for the period will be announced next week.

"It appears that Chinese activity is escalating at sea and in the air," Admiral Katsutoshi Kawano, chief of the Japanese Self-Defence Forces, said at a regular press briefing in Tokyo.

Japan is embroiled in a dispute with China in the East China Sea over ownership of a group of islands which lie about 220 km (140 miles) northeast of Taiwan known as the Senkakus in Tokyo and the Diaoyu islands in Beijing.

Japan is worried that China is escalating its activity in the East China Sea in response to Tokyo's pledge to support countries in Southeast Asia, including the Philippines and Vietnam, that oppose China's territorial claims in the South China Sea.

Kawano said that Japan was "very concerned," about how China will react to a ruling by The Hague-based Permanent Court of Arbitration in a case brought by the Philippines on China's claims. The ruling is due on July 12.

Manila is contesting China's claim to about 90 percent of the South China Sea, arguing it violates the U.N. Convention on the Law of the Sea and restricts its rights to exploit resources within its exclusive economic zone.

China has refused to recognise the case. </s> Two Japanese fighter jets took "provocative actions" at a high speed near a pair of Chinese fighter jets that were carrying out patrols in the East China Sea on June 17, China's defence ministry said in a microblog statement on Monday, without specifying where exactly the incident took place.

The Japanese planes used fire-control radar to "light up" the Chinese aircraft, the statement added.

Japan's senior military officer has acknowledged there was a scramble but has denied that any radar lock by the Chinese jet occurred or that the incident turned dangerous.

"The Japanese plane's provocative actions caused an accident in the air, endangering the safety of personnel on both sides, and destroying the peace and stability in the region," China's Defence Ministry said, adding the Chinese aircraft "responded resolutely".

China called on Japan to cease all provocative action, the statement added.

The statement about the incident comes after Japan's top military commander accused China of escalating military activity in the East China Sea, saying Japanese emergency scrambles to counter Chinese jets almost doubled over the past three months.

Japan is embroiled in a dispute with China in the East China Sea over ownership of a group of islands which lie about 220 km (140 miles) northeast of Taiwan, known as the Senkakus in Tokyo and the Diaoyu islands in Beijing.

Japan is worried that China is escalating its activity in the East China Sea in response to Tokyo's pledge to support countries in Southeast Asia, including the Philippines and Vietnam, that oppose China's territorial claims in the South China Sea.
According to the Japanese Government, three of them came down in Japan's Exclusive Economic Zone.