"Japanese authorities detained the Chinese captain with the application of domestic Japanese law, which is an attempt to demonstrate Japan's administration of the Diaoyu Islands. But that cannot prove the islands are not a part of Chinese territory," said Professor Guan Jianqiang, an international law expert at the Shanghai-based East China University of Political Science and Law.

"For instance, both the 1943 Cairo Declaration and the 1945 Potsdam Proclamation reaffirmed Chinese sovereignty over Taiwan and its surrounding islands, including the Diaoyu Islands," Guan said.

"They entered our territorial waters, destroyed our property (the fishing boat), and seized our citizens. What do you call that?" said "fenghuang802" in a message posted at bbs.ifeng.com.

"What the Japanese seized was not Zhan Qixiong, the trawler's captain, but the dignity of the Chinese nation," said "Li Weihua" at t.sina.com.cn.

"We must firmly boycott Japanese goods. They are making so much money from us Chinese while hurting us so deeply. If you're a good Chinese person, you won't buy Japanese goods," said "zzwghwgh" at tianya.cn.

"I hope the Chinese government adopts an even tougher attitude in tackling this issue. Don't let the public lose confidence," said "huoxing" at bbs.163.com.