Seven of the 14 Chinese activists arrested by Japanese for landing on one of the Diaoyu islands Wednesday arrived at Naha airport in southwest Japan Friday afternoon to fly back to Hong Kong.

The other group of seven will return later Friday on the boat they came from, according to a spokesman from Chinese embassy in Japan. But exact time for them to depart remains unknown.

Japanese Cabinet announced Friday morning that it decided to release all 14 Chinese activists who were arrested on Wednesday after seven of them landed on one of the Diaoyu Islands in East China Sea.

China's Foreign Ministry on Friday said after Japan's announcement that China holds a "firm stance" over the Diaoyu Islands, and any of Japan's unilateral moves against Chinese nationals is illegal and invalid.

The 14 Chinese activists, despite obstruction by Japan Coast Guard patrol ships, arrived at Diaoyu Islands by a Hong Kong fishing vessel on Wednesday to assert China's territorial claim to the islands.

China on Wednesday lodged solemn representations with Japan on the latter's illegal detention of Chinese nationals on the Diaoyu Islands, and on Thursday once again urged Japan to "immediately and unconditionally" release Chinese nationals illegally detained over the Diaoyu Islands issue.