Beijing - Beijing on Tuesday rejected Japanese protests against two Chinese ships entering the waters around a group of disputed islands in the East China Sea.
The Diaoyu Islands have been part of China since "ancient times" Liu Jinachao, a Foreign Ministry spokesman, was quoted as saying by the official Xinhua news agency.
"The usual cruising of the Chinese ships within Chinese seas is irreproachable," he said.
The islands, a source of bilateral tension for many years, are called Diaoyu in China and Senkaku in Japan.
Japan has held the islands since China9s defeat in the Sino-Japanese War in 1895, but they are also claimed by China and Taiwan.