SHANGHAI - More than 50 scholars from the Chinese mainland, Hong Kong, Macao, Taiwan and abroad convened in Shanghai on Wednesday to defend China's sovereignty over the Diaoyu Islands with historical and legal evidence.

The seminar, organized by the Shanghai Institute for International Studies, Fangxia Cultural Exchange Association and the National Society of Taiwan Studies, came a day after the Chinese government issued a white paper asserting the country's indisputable sovereignty over the Diaoyu Island and its affiliated islets, referred to in the document as "the inherent territory" of China.

Scholars discussed historical and legal evidence for China's sovereignty over the Diaoyu islands, the impact of Japan's "purchase" of part of them and methods for the Chinese to protect their country's right to the territory. Trends in the dispute's development and its impact on Sino-Japanese relations were also covered.

"The islands are part of China's inherent territory," said Xu Dunxin, former Chinese embassador to Japan. "They are precious heritage from the forefathers of all the Chinese people."

He said Japan's "purchase," a serious violation of China's sovereignty, has greatly hurt Chinese people's feelings.

The 40th anniversary of the normalization of China-Japan relations, which falls this year, has been overshadowed by Japan's actions this month amid China's repeated objections.

Zheng Hailin, a researcher with the Chinese University of Hong Kong's Institute of Asia-Pacific Studies, told the seminar that the Diaoyu Islands were first discovered, named and exploited by the Chinese.

Zheng, an expert on the islands, said his latest study found that in maps published by countries including Britain, the United States and France after 1774, the English naming of the Diaoyu Islands and their affiliated islets was phonetically based on the local dialects of east China's Fujian Province.

Claims that the islands were first discovered and exploited by Japan are totally groundless, according to the researcher.

Other scholars criticized Japan's latest move from a global perspective, saying it is a serious challenge to international order after World War II.

The scholars urged the Japanese government to refrain from infringing on China's sovereignty and called on it to take corrective action to avoid jeopardizing bilateral relations.