Three Hong Kong and Macau activists who planned to lodge a protest with Prime Minister Shinzo Abe in Beijing over a string of uninhabited islets in the East China Sea that are the crux of territorial disputes between China, Taiwan and Japan were barred from entering the Chinese capital, a group member said.

Chan Miu-tak, former head of the Action Committee for Defending the Diaoyu Islands, whose members landed on one of the Japan-controlled Senkaku islets in 2012 to declare Chinese sovereignty, and two other group members were sent back on a plane for Hong Kong after they landed in Beijing, group member Tsang Kin-shing said.

"They managed to only tell me that they are being put on a returning flight," Tsang said.

The trio, who had planned a protest during the upcoming Asia-Pacific Economic Cooperation summit demanding Abe apologize and compensate China for Japan occupying the islets and distorting Chinese history, would have been joined by mainland activists for their action in Beijing on Friday.

In August 2012, members of the activist group landed on one of the Senkaku Islands, which are known as Diaoyu in China and Tiaoyutai in Taiwan. They were arrested by Japanese authorities and deported.

Numerous attempts by the group to repeat their effort afterwards were futile as Hong Kong authorities have barred their boat from leaving Hong Kong waters.

The relationship between China and Japan has remained tense following the Japanese government's purchase of most of the Senkakus from a private Japanese owner in 2012, which led to massive anti-Japan protests across dozens of Chinese cities, and by Abe's visit to the war-linked Yasukuni Shrine in Tokyo last year.