Japanese officials confirm a boat carrying activists from Hong Kong has reached waters surrounding a group of disputed islands in the East China sea. The islands, known as the Senkakus in Japan, are controlled by the Japanese but both China and Taiwan lay claim to them, The Wall Street Journal reported Wednesday. The arrival of the activists is the latest in a series of incidents involving territorial disputes between Japan and its neighbors. A spokesman for the Chinese foreign ministry warned Japan must refrain from taking any action that could endanger the life and property of Chinese citizens, the official Chinese news service Xinhua reported. The boat from Hong Kong has 14 activists along with journalists and a crew aboard. Initially groups from Hong Kong, Taiwan and mainland China planned to take the voyage but the Taiwanese and Chinese activists withdrew. The islands have been a source of tension for many years with pro-Chinese groups making repeated attempts to land on them.