This file picture taken on September 2 shows a team of Japanese surveyors on a rubber boat heading to the Diaoyu Islands. Photo: AFP

China has announced the base points and baselines of the territorial waters of the Diaoyu Islands and plans to conduct routine monitoring of the islands and their adjacent waters, as part of the strongest reaffirmation of the country's sovereignty over the islands in the East China Sea yet.

The statement came amid warnings by top Chinese leaders, including President Hu Jintao, Premier Wen Jiabao and top legislator Wu Bangguo, over a decision by the Japanese government at a ministerial meeting Monday to "purchase" part of China's Diaoyu Islands.

Liu Jiangyong, a vice dean of the Institute of Modern International Relations at Tsinghua University, said the statement is a corresponding move against Japan's illegal purchase and China would act in accordance with Japan's future actions"

The approved purchase plan has sparked anger among the Chinese public. Within hours after the news being published on news portal sina.com, more than 10,000 Web users left comments expressing their dissatisfaction and calling for severe countermeasures from the Chinese government.

Many Web users and news commentators hailed China's moves as constituting a major policy shift, with a popular Weibo thread reading, "The statement means China does not admit there is a territorial dispute in the area, affirming its absolute sovereignty over the islands … China may carry out a series of measures to safeguard it and the possibility of resorting to force cannot be ruled out."

"The Japanese government's move is a further step away from peacefully resolving the Diaoyu Islands dispute, and has severely spoiled the atmosphere of the 40th anniversary of China-Japan ties since diplomatic normalization, hurting the feelings of the Chinese people," Qu Xing, director of the China Institute of International Studies, told the Global Times Monday.

The row has also impacted entertainment circles. On Monday, Chinese actor Wen Zhang said at an awards ceremony for the 9th China Golden Eagle TV Art Festival that "the Diaoyu Islands belong to China." As of yesterday, over 10 million Sina Weibo users voiced support for him. Chinese movie actress Li Bingbing did not appear at the movie premiere of the film "Resident Evil: Retribution" in Tokyo due to the ongoing dispute.

"The anger expressed by Web users and the public is understandable. The Diaoyu Islands dispute was initiated solely by the Japanese side, which has acted in violation of the China-Japan consensus," said Gao Hong, deputy director of the Institute of Japanese Studies at the Chinese Academy of Social Sciences, noting that the Chinese government will take countermeasures if Japan continues to go on the wrong path and crosses the line of what China can tolerate. "The consequences will be on Japan," he said.

According to Qu, there would be long-term complications if the Japanese government managed to "gain possession of the islands" from their so-called private owners. There will be much greater risks of Sino-Japanese tensions spiraling out of control over the issue, he said, noting in a previous interview with the Global Times that China could issue a new law to further lay claim to the islands.

Despite the Japanese government's statement, which insisted that there would be fewer risks if the central government "bought" the islands instead of Tokyo Governor Shintaro Ishihara, there is no essential difference between the Japanese government's plan and Ishihara's claim, according to Gao.

The question of the Diaoyu Islands has historical roots, and with growing national power and consistent diplomatic efforts, China has always tried to solve the dispute, he said. "It will be a long process and the Chinese people should have faith in the Chinese government and stay calm."

Also on Monday, Japanese Chief Cabinet Secretary Osamu Fujimura said at a press conference that the Japanese government hopes the purchase will not undermine overall bilateral relations with China.

The ministerial meeting came one day after Chinese President Hu Jintao met with Japanese Prime Minister Yoshihiko Noda Sunday on the sidelines of the 20th informal economic leaders' meeting of the Asia-Pacific Economic Cooperation (APEC) forum and made clear China's position on its relations with Japan and on the Diaoyu Islands issue.

The Chinese government stands firm on the issue of safeguarding its territorial sovereignty, President Hu said, adding Japan must fully recognize the gravity of the situation and should not make wrong decisions.

Whatever means the Japanese side uses to "purchase the islands" are illegal and invalid and China firmly opposes such moves, he said, urging Japan to work with the Chinese side to maintain the overall development of the two countries' relations.

Premier Wen said Monday China will "absolutely make no concession" on issues concerning its sovereignty and territorial integrity.

"China is closely following the development of the issue and will take necessary measures to protect its territorial sovereignty," Foreign Ministry spokesperson Hong Lei said on the same day.

The Japanese central government announced last Tuesday that the Kurihara family, which claims to own the Diaoyu Islands in the East China Sea, has agreed to sell three of the five uninhabited islands at 2.05 billion yen ($26.15 million).

The Japanese government will decide to buy the islands with government reserve funds at Tuesday's cabinet meeting and sign the official contract for the purchase with the Kurihara family.

Many Japanese media outlets speculated that the purchase will escalate Sino-Japanese tensions and result in retaliatory measures from the Chinese side, China Central Television reported.