Public demonstrations of support for sovereignty claims over the Diaoyu Islands are being muffled by the authorities, who fear the patriotic movement could backfire. A Beijing-based activist said the authorities had warned him to halt protests against the Japanese presence on the archipelago as early as the second day after Deng Xiaoping's death in February. The activist said: 'Officials of more than one department have approached me. They also asked my friends to pass on the message. 'I've planned not to contact other Diaoyu petitioners around June 4, which is a sensitive period in Chinese politics. I don't want the Government to discredit our activities and smear us as rioters.' He said he was told the authorities did not want interference as they prepared for the Hong Kong handover and the 15th Party Congress. Nanjing-based Diaoyu activist Xu Shuiliang said the Government had maintained a tight grip on their movements. 'It's very difficult to organise any activity,' he said. 'The authorities prefer a low profile on the issue.' Mr Xu said the mainland media paid little attention to Monday's protest by about 20 vessels from Taiwan and Hong Kong near the island chain. 'I am pessimistic about a quick settlement with Japan,' he said. 'So far, China only announces a war of words over the dispute, but there is no action.' Tong Zeng, a prominent figure behind mainland protests, said Beijing should arrest those Japanese who landed on the islands without Chinese permission. He urged the Government to protect its national fishing in the area. Taiwan Vice-President Lien Chan criticised Japan yesterday for its handling of the Diaoyu dispute. David Lee, director of the Government Information Office, said: 'Mr Lien was extremely unhappy about the way the Japanese Government dealt with the incident.' The Taiwan press quoted Mr Lien as asking Japan to show restraint on the issue.