Chinese ships enter disputed waters

Chinese surveillance ships sail in the East China Sea, near islands at the centre of a territorial dispute.

On Friday (September 14) tensions flared yet again between China and Japan as the six ships sailed close to islands claimed by both nations.

Chinese state media said the ships were carrying out surveillance and enforcing maritime rights.

But Japan said China was intruding on its territorial waters.

On a visit to Australia, Japanese Foreign Minister Koichiro Gemba said a protest had been lodged with the Chinese ambassador.

SOUNDBITE: JAPANESE FOREIGN MINISTER KOICHIRO GEMBA SAYING (English):

"And I'd like to underscore that we should never let the situation escalate and we have strong hopes for the Chinese to respond to the situation in an appropriate and also a calm manner."

In Beijing, protesters gathered for a forth day, angry at claims Japan bought the islands from a private owner.

Known as Senkaku in Japan and Daioyu in China, the island chain sits near potentially lucrative oil and gas fields.

The long-running dispute is one of many dogging ties in Asia, as nations row over rival territorial claims.