China deployed ships to waters near islands disputed with Japan for a record 28 hours, drawing a formal protest as it repeated a strategy of pressing its territorial claims through bolder projections of maritime power.
Ships from China's newly formed coastguard remained in the Japanese-controlled waters for the longest time since Japan bought the Diaoyu, or Senkaku, islands last year, Cabinet Secretary Yoshihide Suga said at a briefing in Tokyo yesterday. Japan's Foreign Ministry summoned a Chinese diplomat and "sternly protested", he said.
Four China Coast Guard ships spent more than a day in Japanese-controlled waters around the islands, part of the time stationary within five kilometres of the Nan, or Minami, islet, according to the Japan Coast Guard.
The ships left the waters around the East China Sea islands at about noon yesterday.
"It is clear that the Senkaku Islands are Japan's territory, in terms of history and international law," Suga said. "This incursion into our territorial waters is the longest since our government bought the islands in September. It is extremely regrettable and we cannot accept it."
The Chinese ships forced out Japanese "right-wingers" from waters around the disputed islands, the Chinese embassy in Japan said in a statement.
The chargé d'affaires filed a diplomatic protest yesterday over the incident and requested that the Japanese ships immediately leave the territory and prevent any future incidents, it said.
Shi Yinhong, a regional security expert with Renmin University's School of International Relations, said that the ratcheting up of maritime patrols was a response to the increase in hawkish rhetoric from Japan's ruling Liberal Democratic Party.
"It is a counter action to [Japanese Prime Minister Shinzo] Abe's repeated tough message to China," Shi said, noting the Japanese prime minister's recent visit to the islands near the Diaoyus and his pledges to "never make concessions" in the dispute.
On Tuesday, Japan unveiled its largest warship since the second world war. The Chinese Defence Ministry said yesterday that the region must be on alert over Japan's defence build-up.
Shanghai-based military expert Ni Lexiong said the growing maritime activities in the East China Sea were designed to send message to countries involved in territorial disputes with Beijing in the South China Sea.
"China's dispute with Japan over the Diaoyus is always seen as a test of its determination and ability to deal with the territorial disputes with several [Association of Southeast Asian Nations] nations over the Spratlys and other islands in the South China Sea," said Ni, who is director of the Sea Power and Defence Policy Research Institute at the Shanghai University of Political Science and Law.