China's non-Communist parties on Saturday released a joint statement expressing strong indignation over, and condemnation of, Japan's so-called "purchase" of the Diaoyu Islands.

The statement was issued by the central committees of the Revolutionary Committee of the Chinese Kuomintang, Chinese Democratic League, China National Democratic Construction Association, China Association for Promoting Democracy, Chinese Peasants and Workers Democratic Party, China Zhi Gong Party, Jiu San Society, and Taiwan Democratic Self-Government League respectively.

Ignoring the Chinese government's resolute opposition to the move, the Japanese government announced that it would "purchase" the islands to "nationalize them" on Sept. 10, overtly infringing upon China's territorial sovereignty and seriously hurting the Chinese people's feelings, said the statement.

"China's non-Communist parties voice strong indignation over and rigorously condemn the move," it said.

"Most non-Communist parties were born during the time of war against Japan's invasion (in the 1930s and '40s). Having had fought for the Chinese nation's independence and liberation, these parties, traditionally being patriotic and peace-loving, are staunch guards of the nation's territorial sovereignty," the statement added.

"The Chinese nation is peace-loving, so are its people. China has no intention to impinge on other countries' territorial sovereignty, but will not tolerate any infringement on its own sovereignty by other countries. Long gong is the time when the Chinese nation was bullied by others," it said.

"If the Japanese government underestimates Chinese people's determination, courage or strength, it would be a miscalculation and they are doomed to fail," it added.

The statement reiterated that the Diaoyu Island and its affiliated islets have been an inherent part of Chinese territory since ancient times.

The China Association for Science and Technology (CAST) also stated on Saturday that the organization strongly opposes to and condemns the vile behavior of the Japanese government.

The CAST statement said, "The great number of Chinese scientists and engineers will not tolerate any encroachment upon China's sacred territory by any country, and will firmly stand behind the government in any necessary measures that safeguard the country's territorial sovereignty."