Seven Chinese activists were arrested by Japanese authorities Wednesday after landing on one of the disputed Senkaku Islands in the East China Sea, Japanese officials said.

The morning landing on the uninhabited islet prompted Japan to lodge a strong protest with China. Japan, China and Taiwan all claim the islands, which have a total land mass of about 7 sq. km and are known as Diaoyu in China and as Tiaoyutai in Taiwan.

"In terms of both history and international law, there can be no doubt that the Senkaku Islands are part of our territory," Chief Cabinet Secretary Yasuo Fukuda told a regular news conference in Tokyo in the morning.