A senior Chinese military officer has said the Ryukyu Islands -- which include Okinawa and its US military bases -- "do not belong to Japan", as a territorial row mounts between the Asian powers.

The comments by People's Liberation Army Major General Luo Yuan were published by the China News Service website Tuesday, after the country's leading newspaper last week carried a call to review Tokyo's sovereignty over the chain.

Luo emphasised that the islands were historically in a vassal relationship with imperial Chinese dynasties.

Those ties did not necessarily mean they were part of China, he said, adding: "But we can be certain of one point. The Ryukyus don't belong to Japan."

"(If) the Ryukyus don't belong to you," he said, referring to Tokyo, "how can you talk about the Diaoyus?"

China and Japan have been in a long-running dispute over islands in the East China Sea that Tokyo administers as the Senkakus, but Beijing claims as the Diaoyus.

The row intensified last year after Japan purchased islands in the chain it did not already own, sparking outrage in China, with anti-Japanese demonstrations taking place in Chinese cities.

Chinese vessels regularly enter waters around the islands and Japan has scrambled jets to ward off Chinese flights in the area, stoking fears of armed conflict.

Analysts have said questions in China about the Ryukyus' status are probably aimed at pressuring Japan to make concessions in the dispute over the islands, which are administratively part of Okinawa prefecture.

Luo seemed to back up such a view, saying that by raising the issue of the Ryukyus, China struck a blow at Japan's "soft spot".

Last Wednesday, the People's Daily, China's most-circulated newspaper and the mouthpiece of the ruling Communist party, carried an article by scholars arguing that the country may have rights to the Ryukyus.

Japan says the islands are its territory and are accepted as such internationally.

Before being annexed into Japan in the late 19th century, the independent Ryukyu kingdom, centred on Okinawa, paid tribute to China for centuries -- as did numerous other traditional Asian states -- often receiving favourable trading rights in return.

Okinawa hosts major US air force and marine bases and is home to 1.3 million people. The US military occupied Okinawa and some other islands in the Ryukyu chain for 27 years after the end of World War II, returning them to Japan on May 15, 1972.